ABSTRACT
Follicular helper T cells (TFH cells) and follicular regulatory T cells (TFR cells) regulate the quantity and quality of humoral immunity. Although both cell types express the costimulatory receptor ICOS and require the transcription factor Bcl-6 for their differentiation, the ICOS-dependent pathways that coordinate their responses are not well understood. Here we report that activation of ICOS in CD4(+) T cells promoted interaction of the p85α regulatory subunit of the signaling kinase PI(3)K and intracellular osteopontin (OPN-i), followed by translocation of OPN-i to the nucleus, its interaction with Bcl-6 and protection of Bcl-6 from ubiquitin-dependent proteasome degradation. Post-translational protection of Bcl-6 by OPN-i was essential for sustained responses of TFH cells and TFR cells and regulation of the germinal center B cell response to antigen. Thus, the p85α-OPN-i axis represents a molecular bridge that couples activation of ICOS to Bcl-6-dependent functional differentiation of TFH cells and TFR cells; this suggests new therapeutic avenues to manipulate the responses of these cells.
Subject(s)
Class Ia Phosphatidylinositol 3-Kinase/immunology , Inducible T-Cell Co-Stimulator Protein/immunology , Osteopontin/immunology , Proto-Oncogene Proteins c-bcl-6/immunology , T-Lymphocytes, Helper-Inducer/immunology , T-Lymphocytes, Regulatory/immunology , Animals , Cell Differentiation/immunology , Class Ia Phosphatidylinositol 3-Kinase/genetics , Female , Flow Cytometry , Germinal Center/immunology , Inducible T-Cell Co-Stimulator Protein/genetics , Male , Mice, Inbred C57BL , Mice, Knockout , Osteopontin/genetics , Protein Isoforms , Proto-Oncogene Proteins c-bcl-6/genetics , RNA, Messenger/chemistry , RNA, Messenger/genetics , Random Allocation , Reverse Transcriptase Polymerase Chain Reaction , Specific Pathogen-Free OrganismsABSTRACT
Periodic spin-orbit motion is ubiquitous in nature, observed from electrons orbiting nuclei to spinning planets orbiting the Sun. Achieving autonomous periodic orbiting motions, along circular and noncircular paths, in soft mobile robotics is crucial for adaptive and intelligent exploration of unknown environments-a grand challenge yet to be accomplished. Here, we report leveraging a closed-loop twisted ring topology with a defect for an autonomous soft robot capable of achieving periodic spin-orbiting motions with programmed circular and re-programmed irregular-shaped trajectories. Constructed by bonding a twisted liquid crystal elastomer ribbon into a closed-loop ring topology, the robot exhibits three coupled periodic self-motions in response to constant temperature or constant light sources: inside-out flipping, self-spinning around the ring center, and self-orbiting around a point outside the ring. The coupled spinning and orbiting motions share the same direction and period. The spinning or orbiting direction depends on the twisting chirality, while the orbital radius and period are determined by the twisted ring geometry and thermal actuation. The flip-spin and orbiting motions arise from the twisted ring topology and a bonding site defect that breaks the force symmetry, respectively. By utilizing the twisting-encoded autonomous flip-spin-orbit motions, we showcase the robot's potential for intelligently mapping the geometric boundaries of unknown confined spaces, including convex shapes like circles, squares, triangles, and pentagons and concaves shapes with multi-robots, as well as health monitoring of unknown confined spaces with boundary damages.
ABSTRACT
Hypoxia signaling influences tumor development through both cell-intrinsic and -extrinsic pathways. Inhibiting hypoxia-inducible factor (HIF) function has recently been approved as a cancer treatment strategy. Hence, it is important to understand how regulators of HIF may affect tumor growth under physiological conditions. Here we report that in aging mice factor-inhibiting HIF (FIH), one of the most studied negative regulators of HIF, is a haploinsufficient suppressor of spontaneous B cell lymphomas, particular pulmonary B cell lymphomas. FIH deficiency alters immune composition in aged mice and creates a tumor-supportive immune environment demonstrated in syngeneic mouse tumor models. Mechanistically, FIH-defective myeloid cells acquire tumor-supportive properties in response to signals secreted by cancer cells or produced in the tumor microenvironment with enhanced arginase expression and cytokine-directed migration. Together, these data demonstrate that under physiological conditions, FIH plays a key role in maintaining immune homeostasis and can suppress tumorigenesis through a cell-extrinsic pathway.
Subject(s)
Lymphoma, B-Cell , Repressor Proteins , Animals , Mice , Hypoxia/metabolism , Mixed Function Oxygenases/metabolism , Repressor Proteins/metabolism , Tumor MicroenvironmentABSTRACT
The D2 dopamine receptor (DRD2) is a therapeutic target for Parkinson's disease1 and antipsychotic drugs2. DRD2 is activated by the endogenous neurotransmitter dopamine and synthetic agonist drugs such as bromocriptine3, leading to stimulation of Gi and inhibition of adenylyl cyclase. Here we used cryo-electron microscopy to elucidate the structure of an agonist-bound activated DRD2-Gi complex reconstituted into a phospholipid membrane. The extracellular ligand-binding site of DRD2 is remodelled in response to agonist binding, with conformational changes in extracellular loop 2, transmembrane domain 5 (TM5), TM6 and TM7, propagating to opening of the intracellular Gi-binding site. The DRD2-Gi structure represents, to our knowledge, the first experimental model of a G-protein-coupled receptor-G-protein complex embedded in a phospholipid bilayer, which serves as a benchmark to validate the interactions seen in previous detergent-bound structures. The structure also reveals interactions that are unique to the membrane-embedded complex, including helix 8 burial in the inner leaflet, ordered lysine and arginine side chains in the membrane interfacial regions, and lipid anchoring of the G protein in the membrane. Our model of the activated DRD2 will help to inform the design of subtype-selective DRD2 ligands for multiple human central nervous system disorders.
Subject(s)
Cryoelectron Microscopy , GTP-Binding Protein alpha Subunits, Gi-Go/chemistry , GTP-Binding Protein alpha Subunits, Gi-Go/ultrastructure , Membrane Lipids/metabolism , Membranes, Artificial , Receptors, Dopamine D2/chemistry , Receptors, Dopamine D2/ultrastructure , Bromocriptine/chemistry , Bromocriptine/metabolism , Dopamine/chemistry , Dopamine/metabolism , GTP-Binding Protein alpha Subunits, Gi-Go/metabolism , Humans , Membrane Lipids/chemistry , Models, Molecular , Protein Conformation , Receptors, Dopamine D2/agonists , Receptors, Dopamine D2/metabolism , Signal TransductionABSTRACT
Swine coronavirus-porcine epidemic diarrhea virus (PEDV) with specific susceptibility to pigs has existed for decades, and recurrent epidemics caused by mutant strains have swept the world again since 2010. In this study, single-cell RNA sequencing was used to perform for the first time, to our knowledge, a systematic analysis of pig jejunum infected with PEDV. Pig intestinal cell types were identified by representative markers and identified a new tuft cell marker, DNAH11. Excepting enterocyte cells, the goblet and tuft cells confirmed susceptibility to PEDV. Enrichment analyses showed that PEDV infection resulted in upregulation of cell apoptosis, junctions, and the MAPK signaling pathway and downregulation of oxidative phosphorylation in intestinal epithelial cell types. The T cell differentiation and IgA production were decreased in T and B cells, respectively. Cytokine gene analyses revealed that PEDV infection downregulated CXCL8, CXCL16, and IL34 in tuft cells and upregulated IL22 in Th17 cells. Further studies found that infection of goblet cells with PEDV decreased the expression of MUC2, as well as other mucin components. Moreover, the antimicrobial peptide REG3G was obviously upregulated through the IL33-STAT3 signaling pathway in enterocyte cells in the PEDV-infected group, and REG3G inhibited the PEDV replication. Finally, enterocyte cells expressed almost all coronavirus entry factors, and PEDV infection caused significant upregulation of the coronavirus receptor ACE2 in enterocyte cells. In summary, this study systematically investigated the responses of different cell types in the jejunum of piglets after PEDV infection, which deepened the understanding of viral pathogenesis.
Subject(s)
Coronavirus Infections , Porcine epidemic diarrhea virus , Swine , Animals , Porcine epidemic diarrhea virus/genetics , Transcriptome , Intestine, Small/pathology , Intestines/pathology , Sequence Analysis, RNAABSTRACT
BACKGROUND: Gastric Cancer (GC) characteristically exhibits heterogeneous responses to treatment, particularly in relation to immuno plus chemo therapy, necessitating a precision medicine approach. This study is centered around delineating the cellular and molecular underpinnings of drug resistance in this context. METHODS: We undertook a comprehensive multi-omics exploration of postoperative tissues from GC patients undergoing the chemo and immuno-treatment regimen. Concurrently, an image deep learning model was developed to predict treatment responsiveness. RESULTS: Our initial findings associate apical membrane cells with resistance to fluorouracil and oxaliplatin, critical constituents of the therapy. Further investigation into this cell population shed light on substantial interactions with resident macrophages, underscoring the role of intercellular communication in shaping treatment resistance. Subsequent ligand-receptor analysis unveiled specific molecular dialogues, most notably TGFB1-HSPB1 and LTF-S100A14, offering insights into potential signaling pathways implicated in resistance. Our SVM model, incorporating these multi-omics and spatial data, demonstrated significant predictive power, with AUC values of 0.93 and 0.84 in the exploration and validation cohorts respectively. Hence, our results underscore the utility of multi-omics and spatial data in modeling treatment response. CONCLUSION: Our integrative approach, amalgamating mIHC assays, feature extraction, and machine learning, successfully unraveled the complex cellular interplay underlying drug resistance. This robust predictive model may serve as a valuable tool for personalizing therapeutic strategies and enhancing treatment outcomes in gastric cancer.
Subject(s)
Drug Resistance, Neoplasm , Stomach Neoplasms , Humans , Antineoplastic Agents/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Deep Learning , Drug Resistance, Neoplasm/drug effects , Fluorouracil/therapeutic use , Immunotherapy/methods , Multiomics , Oxaliplatin/therapeutic use , Precision Medicine/methods , Signal Transduction/drug effects , Stomach Neoplasms/drug therapy , Stomach Neoplasms/genetics , Stomach Neoplasms/immunologyABSTRACT
Soft robots that can harvest energy from environmental resources for autonomous locomotion is highly desired; however, few are capable of adaptive navigation without human interventions. Here, we report twisting soft robots with embodied physical intelligence for adaptive, intelligent autonomous locomotion in various unstructured environments, without on-board or external controls and human interventions. The soft robots are constructed of twisted thermal-responsive liquid crystal elastomer ribbons with a straight centerline. They can harvest thermal energy from environments to roll on outdoor hard surfaces and challenging granular substrates without slip, including ascending loose sandy slopes, crossing sand ripples, escaping from burying sand, and crossing rocks with additional camouflaging features. The twisting body provides anchoring functionality by burrowing into loose sand. When encountering obstacles, they can either self-turn or self-snap for obstacle negotiation and avoidance. Theoretical models and finite element simulation reveal that such physical intelligence is achieved by spontaneously snapping-through its soft body upon active and adaptive soft body-obstacle interactions. Utilizing this strategy, they can intelligently escape from confined spaces and maze-like obstacle courses without any human intervention. This work presents a de novo design of embodied physical intelligence by harnessing the twisting geometry and snap-through instability for adaptive soft robot-environment interactions.
Subject(s)
Robotics , Decision Making , IntelligenceABSTRACT
Inguinal hernias are some of the most frequently diagnosed conditions in clinical practice and inguinal hernia repair is the most common procedure performed by general surgeons. Studies of inguinal hernias in non-European populations are lacking, though it is expected that such studies could identify novel loci. Further, the cumulative lifetime incidence of inguinal hernia is nine times greater in men than women, however, it is not clear why this difference exists. We conducted a genome-wide association meta-analysis of inguinal hernia risk across 513 120 individuals (35 774 cases and 477 346 controls) of Hispanic/Latino, African, Asian and European descent, with replication in 728 418 participants (33 491 cases and 694 927 controls) from the 23andMe, Inc dataset. We identified 63 genome-wide significant loci (P < 5 × 10-8), including 41 novel. Ancestry-specific analyses identified two loci (LYPLAL1-AS1/SLC30A10 and STXBP6-NOVA1) in African ancestry individuals. Sex-stratified analyses identified two loci (MYO1D and ZBTB7C) that are specific to women, and four (EBF2, EMX2/RAB11FIP2, VCL and FAM9A/FAM9B) that are specific to men. Functional experiments demonstrated that several of the associated regions (EFEMP1 and LYPLAL1-SLC30A10) function as enhancers and show differential activity between risk and reference alleles. Our study highlights the importance of large-scale genomic studies in ancestrally diverse populations for identifying ancestry-specific inguinal hernia susceptibility loci and provides novel biological insights into inguinal hernia etiology.
Subject(s)
Hernia, Inguinal , Asian People , Black People/genetics , Extracellular Matrix Proteins/genetics , Female , Genome , Genome-Wide Association Study , Hernia, Inguinal/genetics , Hernia, Inguinal/surgery , Humans , Intracellular Signaling Peptides and Proteins/genetics , MaleABSTRACT
Conjunctival melanoma (CoM) is a rare but potentially lethal cancer of the eye, with limited therapeutic option for metastases. A better understanding how primary CoM disseminate to form metastases is urgently needed in order to develop novel therapies. Previous studies indicated that primary CoM tumors express Vascular Endothelial Growth Factor (VEGF) and may recruit pro-tumorigenic M2-like macrophages. However, due to a lack of proper models, the expected role of angiogenesis in the metastatic dissemination of CoM is still unknown. We show that cells derived from two CoM cell lines induce a strong angiogenic response when xenografted in zebrafish larvae. CoM cells are highly glycolytic and secrete lactate, which recruits and polarizes human and zebrafish macrophages towards a M2-like phenotype. These macrophages elevate the levels of proangiogenic factors such as VEGF, TGF-ß, and IL-10 in the tumor microenvironment to induce an angiogenic response towards the engrafted CoM cells in vivo. Chemical ablation of zebrafish macrophages or inhibition of glycolysis in CoM cells terminates this response, suggesting that attraction of lactate-dependent macrophages into engrafted CoM cells drives angiogenesis and serves as a possible dissemination mechanism for glycolytic CoM cells.
ABSTRACT
Among pyroelectric materials, Bi0.5Na0.5TiO3 (BNT)-based relaxors are particularly noteworthy due to their significant polarization fluctuation near the depolarization temperature (Td), resulting in a large pyroelectric response. What has been overlooked is the dynamic behavior of inherent polar structures, particularly the temperature-dependent evolution of polar nanoregions (PNRs), which significantly impacts the pyroelectric behavior. Herein, based on the large pyroelectric response origination (the ferroelectric-relaxor phase transition), the mixed nonergodic and ergodic relaxor (NR+ER) critical state is constructed, which is believed to trigger the easily fluctuating polarization state with excellent pyroelectric response. Composition engineering (with Li+, Sr2+, and Ta5+) strategically controls the relaxor process and modulates the dynamic behavior of inherent polar structures by the random field effect. The pyroelectric coefficient of more than 1441 µCm-2K-1 at room temperature (RT), more than 9221 µCm-2K-1 (RT), and ≈107911 µCm-2K-1 (Td) are achieved in the Li+-doped sample, the Sr2+-doped sample, and the (Li++Ta5+) co-doped sample, respectively. This work earns the highest RT pyroelectric coefficient in BNT-based relaxors, which is suitable for pyroelectric applications. Furthermore, it provides a strategy for modulating the pyroelectric performance of BNT-based relaxors.
ABSTRACT
Sympathetic hyperinnervation is the leading cause of fatal ventricular arrhythmia (VA) after myocardial infarction (MI). Cardiac mast cells cause arrhythmias directly through degranulation. However, the role and mechanism of mast cell degranulation in sympathetic remodeling remain unknown. We investigated the role of oxytocin (OT) in stabilizing cardiac mast cells and improving sympathetic innervation in rats. MI was induced by coronary artery ligation. Western blotting, immunofluorescence, and toluidine staining of mast cells were performed to determine the expression and location of target protein. Mast cells accumulated significantly in peri-infarcted tissues and were present in a degranulated state. They expressed OT receptor (OTR), and OT infusion reduced the number of degranulated cardiac mast cells post-MI. Sympathetic hyperinnervation was attenuated as assessed by immunofluorescence for tyrosine hydroxylase (TH). Seven days post-MI, the arrhythmia score of programmed electrical stimulation was higher in vehicle-treated rats with MI than in rats treated with OT. An in vitro study showed that OT stabilized mast cells via the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) signaling pathway. Further in vivo studies on OTR-deficient mice showed worsening mast cell degranulation and worsening sympathetic innervation. OT pretreatment inhibited cardiac mast cell degranulation post-MI and prevented sympathetic hyperinnervation, along with mast cell stabilization via the PI3K/Akt pathway. SIGNIFICANCE STATEMENT: This is the first study to elucidate the role and mechanism of oxytocin (OT) in inflammatory-sympathetic communication mediated sympathetic hyperinnervation after myocardial infarction (MI), providing new approaches to prevent fatal arrhythmias.
Subject(s)
Cell Degranulation , Mast Cells , Myocardial Infarction , Oxytocin , Rats, Sprague-Dawley , Receptors, Oxytocin , Sympathetic Nervous System , Animals , Oxytocin/pharmacology , Oxytocin/metabolism , Myocardial Infarction/drug therapy , Myocardial Infarction/metabolism , Mast Cells/drug effects , Mast Cells/metabolism , Rats , Sympathetic Nervous System/drug effects , Sympathetic Nervous System/metabolism , Male , Cell Degranulation/drug effects , Receptors, Oxytocin/metabolism , Receptors, Oxytocin/antagonists & inhibitors , Mice , Signal Transduction/drug effects , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Arrhythmias, Cardiac/metabolism , Arrhythmias, Cardiac/drug therapy , Arrhythmias, Cardiac/etiologyABSTRACT
Spin and mass properties provide essential clues in distinguishing the origins of coalescing black holes (BHs). With a dedicated semiparametric population model for the coalescing binary black holes (BBHs), we identify two distinct categories of BHs among the GWTC-3 events, which is favored over the one population scenario by a logarithmic Bayes factor (lnB) of 7.5. One category, with a mass ranging from â¼25M_{â} to â¼80M_{â}, is distinguished by the high spin magnitudes (â¼0.75) and consistent with the hierarchical merger origin. The other category, characterized by low spins, has a sharp mass cutoff at â¼40M_{â}, which is natural for the stellar-collapse origin and in particular the pair-instability explosion of massive stars. We infer the local hierarchical merger rate density as 0.46_{-0.24}^{+0.61} Gpc^{-3} yr^{-1}. Additionally, we find that a fraction of the BBHs has a cosine-spin-tilt-angle distribution concentrated preferentially around 1, and the fully isotropic distribution for spin orientation is disfavored by a lnB of -6.3, suggesting that the isolated field evolution channels are contributing to the total population.
ABSTRACT
OBJECTIVES: To investigate the value of extracellular volume (ECV) fraction and fat fraction (FF) derived from dual- energy CT (DECT) for predicting postpancreatectomy acute pancreatitis (PPAP) after pancreatoduodenectomy (PD). METHODS: This retrospective study included patients who underwent DECT and PD between April 2022 and September 2022. PPAP was determined according to the International Study Group for Pancreatic Surgery (ISGPS) definition. Iodine concentration (IC) and FF of the pancreatic parenchyma were measured on preoperative DECT. The ECV fraction was calculated from iodine map images of the equilibrium phase. The independent predictors for PPAP were assessed by univariate and multivariable logistic regression analysis and receiver operating characteristic (ROC) curve analysis. RESULTS: Sixty-nine patients were retrospectively enrolled (median age, 60 years; interquartile range, 55-70 years; 47 men). Of these, nine patients (13.0%) developed PPAP. These patients had lower portal venous phase IC, equilibrium phase IC, FF, and ECV fraction, and higher pancreatic parenchymal-to-portal venous phase IC ratio and pancreatic parenchymal-to-equilibrium phase IC ratio, compared with patients without PPAP. After multivariable analysis, ECV fraction was independently associated with PPAP (odd ratio [OR], 0.87; 95% confidence interval [CI]: 0.79, 0.96; p < 0.001), with an area under the curve (AUC) of 0.839 (sensitivity 100.0%, specificity 58.3%). CONCLUSIONS: A lower ECV fraction is independently associated with the occurrence of PPAP after PD. ECV fraction may serve as a potential predictor for PPAP after PD. CLINICAL RELEVANCE STATEMENT: DECT-derived ECV fraction of pancreatic parenchyma is a promising biomarker for surgeons to preoperatively identify patients with higher risk for postpancreatectomy acute pancreatitis after PD and offer selective perioperative management. KEY POINTS: PPAP is a complication of pancreatic surgery, early identification of higher-risk patients allows for risk mitigation. Lower DECT-derived ECV fraction was independently associated with the occurrence of PPAP after PD. DECT aids in preoperative PAPP risk stratification, allowing for appropriate treatment to minimize complications.
ABSTRACT
Guided by the Global Natural Products Social (GNPS) molecular networking strategy, five undescribed eremophilane-type sesquiterpenoid derivatives (1-5) were isolated and identified from fungus Penicillium roqueforti, which was separated from the root soil of plant Hypericum beanii collected in Shennongjia Forestry District, Hubei Province. Dipeniroqueforins A-B (1-2), representing a lactam-type sesquiterpenoid skeleton with a highly symmetrical and homodimeric 5/6/6-6/6/5 hexacyclic system, are reported within the eremophilane-type family for the first time. Peniroqueforin D (5) represents the first example of a 1,2-seco eremophilane-type sesquiterpenoid derivative featuring an undescribed 7/6-fused ring system. The structures of these compounds were elucidated by various spectroscopic analyses, DP4+ probability analyses, ECD calculations, and single-crystal X-ray diffraction experiments. Furthermore, these isolates were evaluated for cytotoxicity, and the result uncovered that compound 1 displayed broad-spectrum activity. Further mechanistic study revealed that compound 1 could significantly upregulate the mRNA expression of genes related to the oxidative induction, leading to the abnormal ROS levels in tumor cells and ultimately causing tumor cell apoptosis.
Subject(s)
Antineoplastic Agents , Penicillium , Sesquiterpenes , Polycyclic Sesquiterpenes , Molecular Structure , Sesquiterpenes/chemistry , Penicillium/chemistry , Antineoplastic Agents/chemistryABSTRACT
Although the mechanism of NK cell activation is still unclear, the strict calcium dependence remains the hallmark for lytic granule secretion. A plethora of studies claiming that impaired Ca2+ signaling leads to severely defective cytotoxic granule exocytosis accompanied by weak target cell lysis has been published. However, there has been little discussion about the effect of induced calcium signal on NK cell cytotoxicity. In our study, we observed that small-molecule inhibitor UNC1999, which suppresses global H3K27 trimethylation (H3K27me3) of human NK cells, induced a PKD2-dependent calcium signal. Enhanced calcium entry led to unbalanced vesicle release, which resulted into fewer target cells acquiring lytic granules and subsequently being killed. Further analyses revealed that the ability of conjugate formation, lytic synapse formation, and granule polarization were normal in NK cells treated with UNC1999. Cumulatively, these data indicated that induced calcium signal exclusively enhances unbalanced degranulation that further inhibits their cytotoxic activity in human NK cells.
Subject(s)
Calcium Signaling/physiology , Cell Degranulation/immunology , Enhancer of Zeste Homolog 2 Protein/antagonists & inhibitors , Killer Cells, Natural/immunology , TRPP Cation Channels/metabolism , Benzamides/pharmacology , Calcium/metabolism , Cell Line , Enhancer of Zeste Homolog 2 Protein/genetics , Enhancer of Zeste Homolog 2 Protein/metabolism , Histones/metabolism , Humans , Indazoles/pharmacology , Lymphocyte Activation/immunology , Methylation , Piperazines/pharmacology , Pyridones/pharmacologyABSTRACT
Single-atom catalysts (SACs) have attracted great attention for various chemical reactions because of their strong activity, high metal utilization ratio, and low cost. Here, by using the density functional theory (DFT) method, the stability of a single VIII-group metal atom (M = Ni, Pd, Pt) anchored on the defective hexagonal boron nitride (h-BN) sheet and its possible application in oxidative desulfurization (ODS) are investigated. Calculations show that the stability of the single M atom embedded in the h-BN surface with B and N vacancies is strikingly enhanced compared to that on the perfect h-BN surface. The catalytic activities of the defective h-BN-supported single metal atom are further studied by the activation of molecular oxygen and subsequent oxidation of dibenzothiophene (DBT). O2 is activated to the super-oxo state with large interaction energies on three M/VN surfaces. However, among the three M/VB surfaces, only Pt/VB performs efficient activation of O2. The oxidation of DBT proceeds in two steps; the rate-determining step is the initial step, in which activated O2 oxidizes DBT to produce sulfoxide. By comparing the energy barrier in the first reaction step, both Ni/VN and Pt/VB are revealed as promising candidates for the ODS reaction.
ABSTRACT
Sodium and potassium channels, especially Nav1.5 and Kir2.1, play key roles in the formation of action potentials in cardiomyocytes. These channels interact with, and are regulated by, synapse-associated protein 97 (SAP97). However, the regulatory role of SAP97 in myocyte remains incompletely understood. Here, we investigate the function of SAP97 phosphorylation in the regulation of Nav1.5 and Kir2.1 channel complexes and the upstream regulation of SAP97. We found that SAP97 is phosphorylated by casein kinase II (CK2) in vitro. In addition, transfection of casein kinase 2 interacting protein-1 (CKIP-1) into cardiomyocytes to drive CK2 from the nucleus to the cytoplasm, increased SAP97 phosphorylation and Nav1.5 and Kir2.1 current activity. These findings demonstrated that CKIP-1 modulates the subcellular translocation of CK2, which regulates Nav1.5 and Kir2.1 channel complex formation and activity in cardiomyocytes.
Subject(s)
Casein Kinase II , Myocytes, Cardiac , NAV1.5 Voltage-Gated Sodium Channel , Potassium Channels, Inwardly Rectifying , Myocytes, Cardiac/metabolism , Casein Kinase II/metabolism , Potassium Channels, Inwardly Rectifying/metabolism , Potassium Channels, Inwardly Rectifying/genetics , NAV1.5 Voltage-Gated Sodium Channel/metabolism , NAV1.5 Voltage-Gated Sodium Channel/genetics , Animals , Rats , Phosphorylation , Protein Transport , Humans , Carrier Proteins/metabolism , Rats, Sprague-DawleyABSTRACT
Long non-coding RNAs (lncRNAs) are pivotal regulators in heart disease, including myocardial ischemia/reperfusion (I/R) injury. LncRNA just proximal to XIST (JPX) is a molecular switch for X-chromosome inactivation. Enhancer of zeste homolog 2 (EZH2) is a core catalytic subunit of the polycomb repressive complex 2 (PRC2), which is involved in chromatin compaction and gene repression. This study aims to explore the mechanism of JPX regulating the expression of Sarcoplasmic/endoplasmic reticulum Ca2+ ATPase 2a (SERCA2a) by binding to EZH2 and preventing cardiomyocyte I/R damage in vivo and in vitro. First, we constructed mouse myocardial I/R and HL1 cell hypoxia/reoxygenation models, and found that JPX was low expressed in both models. JPX overexpression alleviated cardiomyocyte apoptosis in vivo and in vitro, reduced the I/R-induced infarct size in mouse hearts, lowered the serum cTnI concentration, and promoted mouse cardiac systolic function. The evidence implies that JPX can alleviate I/R-induced acute cardiac damage. Mechanistically, the FISH and RIP assays showed that JPX could bind to EZH2. The ChIP assay revealed EZH2 enrichment at the promoter region of SERCA2a. Both the EZH2 and H3K27me3 levels at the promoter region of SERCA2a were reduced in the JPX overexpression group compared to those in the Ad-EGFP group (P < 0.01). In summary, our results suggested that LncRNA JPX directly bound to EZH2 and reduced the EZH2-mediated H3K27me3 in the SERCA2a promoter region, protecting the heart from acute myocardial I/R injury. Therefore, JPX might be a potential therapeutic target for I/R injury.
Subject(s)
Myocardial Reperfusion Injury , RNA, Long Noncoding , Mice , Animals , Myocardial Reperfusion Injury/genetics , Myocardial Reperfusion Injury/metabolism , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Enhancer of Zeste Homolog 2 Protein/genetics , Enhancer of Zeste Homolog 2 Protein/metabolism , Histones/metabolism , Mice, Inbred C57BL , Myocytes, Cardiac/metabolism , Apoptosis/geneticsABSTRACT
We investigated if poly-lactic acid (PLA) nanopillar array can trigger the differentiation of human epicardial (ADSCs) (heADSCs) into cardiomyocyte-like cells and explored the effects of these cardiomyocyte-like cells on myocardial infarction (MI) in vivo. PLA nanopillar array (200 nm diameter) and plain PLA film (PLA planar) induced heADSCs were marked with carboxyfluorescein. After 7 days, the expressions of myocardiocyte-specific genes were significantly enhanced in cells seeded on PLA nanopillar array compared with that on PLA planar, especially CACNA1C, KCNH2, and MYL2 genes (p < 0.05). However, the expressions of cardiac troponin T (cTNT), KCNQ1, and KCNA5 were lower than those in PLA planar-induced heADSCs (p < 0.05), whereas GATA4 tended to increase with time. The cells with positively stained α-actinin and cTNT were elevated in heADSCs induced by PLA nanopillar array compared with those induced by PLA planar only (p < 0.05). In vivo experiments showed that cardiac function was improved after injecting PLA-nanopillar array-induced heADSCs into the ischemic heart (p < 0.05, compared with PLA planar + MI group). Furthermore, tyrosine hydroxylase density was significantly lower (p < 0.05). PLA nanopillar array directly drives the differentiation of heADSCs into cardiomyocyte-like cells, and the induced heADSCs exhibit a protective effect on ischemic myocardium by improving cardiac function in MI rats.