ABSTRACT
Aphids transmit viruses and are destructive crop pests1. Plants that have been attacked by aphids release volatile compounds to elicit airborne defence (AD) in neighbouring plants2-5. However, the mechanism underlying AD is unclear. Here we reveal that methyl-salicylate (MeSA), salicylic acid-binding protein-2 (SABP2), the transcription factor NAC2 and salicylic acid-carboxylmethyltransferase-1 (SAMT1) form a signalling circuit to mediate AD against aphids and viruses. Airborne MeSA is perceived and converted into salicylic acid by SABP2 in neighbouring plants. Salicylic acid then causes a signal transduction cascade to activate the NAC2-SAMT1 module for MeSA biosynthesis to induce plant anti-aphid immunity and reduce virus transmission. To counteract this, some aphid-transmitted viruses encode helicase-containing proteins to suppress AD by interacting with NAC2 to subcellularly relocalize and destabilize NAC2. As a consequence, plants become less repellent to aphids, and more suitable for aphid survival, infestation and viral transmission. Our findings uncover the mechanistic basis of AD and an aphid-virus co-evolutionary mutualism, demonstrating AD as a potential bioinspired strategy to control aphids and viruses.
Subject(s)
Air , Aphids , Plant Diseases , Plants , Salicylic Acid , Signal Transduction , Aphids/physiology , Aphids/virology , Host Microbial Interactions , Plant Diseases/immunology , Plant Diseases/parasitology , Plant Diseases/prevention & control , Plant Diseases/virology , Plant Proteins/metabolism , Plants/metabolism , Plants/parasitology , Plants/virology , Salicylic Acid/metabolism , Symbiosis , Nicotiana/immunology , Nicotiana/metabolism , Nicotiana/parasitology , Nicotiana/virology , Viral Proteins/metabolism , AnimalsABSTRACT
Aluminum (Al) stress triggers the accumulation of hydrogen peroxide (H2O2) in roots. However, whether H2O2 plays a regulatory role in aluminum resistance remains unclear. In this study, we show that H2O2 plays a crucial role in regulation of Al resistance, which is modulated by the mitochondrion-localized pentatricopeptide repeat protein REGULATION OF ALMT1 EXPRESSION 6 (RAE6). Mutation in RAE6 impairs the activity of complex I of the mitochondrial electron transport chain, resulting in the accumulation of H2O2 and increased sensitivity to Al. Our results suggest that higher H2O2 concentrations promote the oxidation of SENSITIVE TO PROTON RHIZOTOXICITY 1 (STOP1), an essential transcription factor that promotes Al resistance, thereby promoting its degradation by enhancing the interaction between STOP1 and the F-box protein RAE1. Conversely, decreasing H2O2 levels or blocking the oxidation of STOP1 leads to greater STOP1 stability and increased Al resistance. Moreover, we show that the thioredoxin TRX1 interacts with STOP1 to catalyze its chemical reduction. Thus, our results highlight the importance of H2O2 in Al resistance and regulation of STOP1 stability in Arabidopsis (Arabidopsis thaliana).
Subject(s)
Arabidopsis Proteins , Arabidopsis , Transcription Factors/genetics , Transcription Factors/metabolism , Hydrogen Peroxide/metabolism , Arabidopsis Proteins/metabolism , Aluminum/toxicity , Aluminum/metabolism , Gene Expression Regulation, Plant/genetics , Arabidopsis/metabolism , Plant Roots/genetics , Plant Roots/metabolismABSTRACT
TGF-ß signaling is a key player in tumor progression and immune evasion, and is associated with poor response to cancer immunotherapies. Here, we identified ubiquitin-specific peptidase 8 (USP8) as a metastasis enhancer and a highly active deubiquitinase in aggressive breast tumors. USP8 acts both as a cancer stemness-promoting factor and an activator of the TGF-ß/SMAD signaling pathway. USP8 directly deubiquitinates and stabilizes the type II TGF-ß receptor TßRII, leading to its increased expression in the plasma membrane and in tumor-derived extracellular vesicles (TEVs). Increased USP8 activity was observed in patients resistant to neoadjuvant chemotherapies. USP8 promotes TGF-ß/SMAD-induced epithelial-mesenchymal transition (EMT), invasion, and metastasis in tumor cells. USP8 expression also enables TßRII+ circulating extracellular vesicles (crEVs) to induce T cell exhaustion and chemoimmunotherapy resistance. Pharmacological inhibition of USP8 antagonizes TGF-ß/SMAD signaling, and reduces TßRII stability and the number of TßRII+ crEVs to prevent CD8+ T cell exhaustion and to reactivate anti-tumor immunity. Our findings not only reveal a novel mechanism whereby USP8 regulates the cancer microenvironment but also demonstrate the therapeutic advantages of engineering USP8 inhibitors to simultaneously suppress metastasis and improve the efficacy of cancer immunotherapy.
Subject(s)
Extracellular Vesicles , Neoplasms , Receptor, Transforming Growth Factor-beta Type II/metabolism , Ubiquitin Thiolesterase , CD8-Positive T-Lymphocytes/metabolism , Endopeptidases/metabolism , Endosomal Sorting Complexes Required for Transport , Extracellular Vesicles/metabolism , Humans , Neoplasms/genetics , Neoplasms/metabolism , Protein Serine-Threonine Kinases/genetics , Receptor, Transforming Growth Factor-beta Type II/genetics , Receptors, Transforming Growth Factor beta/genetics , Receptors, Transforming Growth Factor beta/metabolism , Signal Transduction , Transforming Growth Factor beta/metabolism , Tumor Microenvironment , Ubiquitin Thiolesterase/metabolismABSTRACT
BACKGROUND: Hyperproliferation of pulmonary arterial smooth muscle cells (PASMCs) and consequent pulmonary vascular remodeling are the crucial pathological features of pulmonary hypertension (PH). Protein methylation has been shown to be critically involved in PASMC proliferation and PH, but the underlying mechanism remains largely unknown. METHODS: PH animal models were generated by treating mice/rats with chronic hypoxia for 4 weeks. SMYD2-vTg mice (vascular smooth muscle cell-specific suppressor of variegation, enhancer of zeste, trithorax and myeloid Nervy DEAF-1 (deformed epidural auto-regulatory factor-1) domain-containing protein 2 transgenic) or wild-type rats and mice treated with LLY-507 (3-cyano-5-{2-[4-[2-(3-methylindol-1-yl)ethyl]piperazin-1-yl]-phenyl}-N-[(3-pyrrolidin-1-yl)propyl]benzamide) were used to investigate the function of SMYD2 (suppressor of variegation, enhancer of zeste, trithorax and myeloid Nervy DEAF-1 domain-containing protein 2) on PH development in vivo. Primary cultured rat PASMCs with SMYD2 knockdown or overexpression were used to explore the effects of SMYD2 on proliferation and to decipher the underlying mechanism. RESULTS: We demonstrated that the expression of the lysine methyltransferase SMYD2 was upregulated in the smooth muscle cells of pulmonary arteries from patients with PH and hypoxia-exposed rats/mice and in the cytoplasm of hypoxia-induced rat PASMCs. More importantly, targeted inhibition of SMYD2 by LLY-507 significantly attenuated hypoxia-induced pulmonary vascular remodeling and PH development in both male and female rats in vivo and reduced rat PASMC hyperproliferation in vitro. In contrast, SMYD2-vTg mice exhibited more severe PH phenotypes and related pathological changes than nontransgenic mice after 4 weeks of chronic hypoxia treatment. Furthermore, SMYD2 overexpression promoted, while SMYD2 knockdown suppressed, the proliferation of rat PASMCs by affecting the cell cycle checkpoint between S and G2 phases. Mechanistically, we revealed that SMYD2 directly interacted with and monomethylated PPARγ (peroxisome proliferator-activated receptor gamma) to inhibit the nuclear translocation and transcriptional activity of PPARγ, which further promoted mitophagy to facilitate PASMC proliferation and PH development. Furthermore, rosiglitazone, a PPARγ agonist, largely abolished the detrimental effects of SMYD2 overexpression on PASMC proliferation and PH. CONCLUSIONS: Our results demonstrated that SMYD2 monomethylates nonhistone PPARγ and inhibits its nuclear translocation and activation to accelerate PASMC proliferation and PH by triggering mitophagy, indicating that targeting SMYD2 or activating PPARγ are potential strategies for the prevention of PH.
Subject(s)
Histone-Lysine N-Methyltransferase , Hypertension, Pulmonary , Hypoxia , Mitophagy , Muscle, Smooth, Vascular , Myocytes, Smooth Muscle , PPAR gamma , Pulmonary Artery , Rats, Sprague-Dawley , Animals , Humans , Male , Mice , Rats , Cell Proliferation , Cells, Cultured , Histone-Lysine N-Methyltransferase/metabolism , Histone-Lysine N-Methyltransferase/genetics , Hypertension, Pulmonary/metabolism , Hypertension, Pulmonary/etiology , Hypertension, Pulmonary/pathology , Hypertension, Pulmonary/genetics , Hypoxia/complications , Hypoxia/metabolism , Methylation , Mice, Inbred C57BL , Mice, Transgenic , Muscle, Smooth, Vascular/metabolism , Muscle, Smooth, Vascular/pathology , Myocytes, Smooth Muscle/metabolism , Myocytes, Smooth Muscle/pathology , PPAR gamma/metabolism , Pulmonary Artery/pathology , Pulmonary Artery/metabolism , Vascular RemodelingABSTRACT
During cell division, cross-linking motors determine the architecture of the spindle, a dynamic microtubule network that segregates the chromosomes in eukaryotes. It is unclear how motors with opposite directionality coordinate to drive both contractile and extensile behaviors in the spindle. Particularly, the impact of different cross-linker designs on network self-organization is not understood, limiting our understanding of self-organizing structures in cells but also our ability to engineer new active materials. Here, we use experiment and theory to examine active microtubule networks driven by mixtures of motors with opposite directionality and different cross-linker design. We find that although the kinesin-14 HSET causes network contraction when dominant, it can also assist the opposing kinesin-5 KIF11 to generate extensile networks. This bifunctionality results from HSET's asymmetric design, distinct from symmetric KIF11. These findings expand the set of rules underlying patterning of active microtubule assemblies and allow a better understanding of motor cooperation in the spindle.
Subject(s)
Kinesins , Microtubules , Oncogene Proteins , Spindle Apparatus , Cell Division , Humans , Kinesins/chemistry , Kinesins/physiology , Microtubules/chemistry , Microtubules/physiology , Oncogene Proteins/chemistry , Oncogene Proteins/physiology , Spindle Apparatus/chemistry , Spindle Apparatus/physiologyABSTRACT
Mosquito blood-feeding behavior is a key determinant of the epidemiology of dengue viruses (DENV), the most-prevalent mosquito-borne viruses. However, despite its importance, how DENV infection influences mosquito blood-feeding and, consequently, transmission remains unclear. Here, we developed a high-resolution, video-based assay to observe the blood-feeding behavior of Aedes aegypti mosquitoes on mice. We then applied multivariate analysis on the high-throughput, unbiased data generated from the assay to ordinate behavioral parameters into complex behaviors. We showed that DENV infection increases mosquito attraction to the host and hinders its biting efficiency, the latter resulting in the infected mosquitoes biting more to reach similar blood repletion as uninfected mosquitoes. To examine how increased biting influences DENV transmission to the host, we established an in vivo transmission model with immuno-competent mice and demonstrated that successive short probes result in multiple transmissions. Finally, to determine how DENV-induced alterations of host-seeking and biting behaviors influence dengue epidemiology, we integrated the behavioral data within a mathematical model. We calculated that the number of infected hosts per infected mosquito, as determined by the reproduction rate, tripled when mosquito behavior was influenced by DENV infection. Taken together, this multidisciplinary study details how DENV infection modulates mosquito blood-feeding behavior to increase vector capacity, proportionally aggravating DENV epidemiology. By elucidating the contribution of mosquito behavioral alterations on DENV transmission to the host, these results will inform epidemiological modeling to tailor improved interventions against dengue.
Subject(s)
Aedes/virology , Dengue Virus/physiology , Dengue/transmission , Dengue/virology , Feeding Behavior/physiology , Host-Pathogen Interactions/physiology , Animals , Behavior, Animal/physiology , Multivariate AnalysisABSTRACT
BACKGROUND AND AIMS: The Glu504Lys polymorphism in the aldehyde dehydrogenase 2 (ALDH2) gene is closely associated with myocardial ischaemia/reperfusion injury (I/RI). The effects of ALDH2 on neutrophil extracellular trap (NET) formation (i.e. NETosis) during I/RI remain unknown. This study aimed to investigate the role of ALDH2 in NETosis in the pathogenesis of myocardial I/RI. METHODS: The mouse model of myocardial I/RI was constructed on wild-type, ALDH2 knockout, peptidylarginine deiminase 4 (Pad4) knockout, and ALDH2/PAD4 double knockout mice. Overall, 308 ST-elevation myocardial infarction patients after primary percutaneous coronary intervention were enrolled in the study. RESULTS: Enhanced NETosis was observed in human neutrophils carrying the ALDH2 genetic mutation and ischaemic myocardium of ALDH2 knockout mice compared with controls. PAD4 knockout or treatment with NETosis-targeting drugs (GSK484, DNase1) substantially attenuated the extent of myocardial damage, particularly in ALDH2 knockout. Mechanistically, ALDH2 deficiency increased damage-associated molecular pattern release and susceptibility to NET-induced damage during myocardial I/RI. ALDH2 deficiency induced NOX2-dependent NETosis via upregulating the endoplasmic reticulum stress/microsomal glutathione S-transferase 2/leukotriene C4 (LTC4) pathway. The Food and Drug Administration-approved LTC4 receptor antagonist pranlukast ameliorated I/RI by inhibiting NETosis in both wild-type and ALDH2 knockout mice. Serum myeloperoxidase-DNA complex and LTC4 levels exhibited the predictive effect on adverse left ventricular remodelling at 6 months after primary percutaneous coronary intervention in ST-elevation myocardial infarction patients. CONCLUSIONS: ALDH2 deficiency exacerbates myocardial I/RI by promoting NETosis via the endoplasmic reticulum stress/microsomal glutathione S-transferase 2/LTC4/NOX2 pathway. This study hints at the role of NETosis in the pathogenesis of myocardial I/RI, and pranlukast might be a potential therapeutic option for attenuating I/RI, particularly in individuals with the ALDH2 mutation.
Subject(s)
Aldehyde Dehydrogenase, Mitochondrial , Extracellular Traps , Leukotriene C4 , Myocardial Reperfusion Injury , Animals , Female , Humans , Male , Mice , Middle Aged , Aldehyde Dehydrogenase, Mitochondrial/genetics , Aldehyde Dehydrogenase, Mitochondrial/metabolism , Benzamides , Benzodioxoles , Disease Models, Animal , Extracellular Traps/metabolism , Leukotriene Antagonists/pharmacology , Leukotriene Antagonists/therapeutic use , Leukotriene C4/antagonists & inhibitors , Leukotriene C4/metabolism , Mice, Knockout , Myocardial Reperfusion Injury/prevention & control , Myocardial Reperfusion Injury/genetics , Myocardial Reperfusion Injury/metabolism , Neutrophils/metabolism , Protein-Arginine Deiminase Type 4/metabolism , ST Elevation Myocardial Infarction/metabolismABSTRACT
The ALMT1 transporter aids malate secretion, chelating Al3+ ions to form nontoxic Al-malate complexes, believed to exclude Al from the roots. However, the extent to which malate secreted by ALMT1 is solely used for the exclusion of Al3+ or can be reutilized by plant roots for internal Al tolerance remains uncertain. In our investigation, we explored the impact of malate secretion on both external and internal Al resistance in Arabidopsis thaliana. Additionally, we delved into the mechanism by which the tonoplast-localized bacterial-type ATP-binding cassette (ABC) transporter complex STAR1/ALS3 promotes the degradation of the Al resistance transcription factor STOP1 to regulate ALMT1 expression. Our study demonstrates that the level of secreted malate influences whether the Al-malate complex is excluded from the roots or transported into root cells. The nodulin 26-like intrinsic protein (NIP) subfamily members NIP1;1 and NIP1;2, located in the plasma membrane, coordinate with STAR1/ALS3 to facilitate Al-malate transport from root apoplasm to the symplasm and eventually to the vacuoles for the internal Al detoxification. ALS3-dependent STAR1 interacts with and promotes the degradation of STOP1, regulating malate exudation. Our findings demonstrate the dual roles of malate exudation in external Al exclusion and Al absorption for internal Al detoxification.
ABSTRACT
Optical coherence tomography (OCT) and its extension OCT angiography (OCTA) have become essential clinical imaging modalities due to their ability to provide depth-resolved angiographic and tissue structural information non-invasively and at high resolution. Within a field of view, the anatomic detail available is sufficient to identify several structural and vascular pathologies that are clinically relevant for multiple prevalent blinding diseases, including age-related macular degeneration (AMD), diabetic retinopathy (DR), and vein occlusions. The main limitation in contemporary OCT devices is that this field of view is limited due to a fundamental trade-off between system resolution/sensitivity, sampling density, and imaging window dimensions. Here, we describe a swept-source OCT device that can capture up to a 12 × 23-mm field of view in a single shot and show that it can identify conventional pathologic features such as non-perfusion areas outside of conventional fields of view. We also show that our approach maintains sensitivity sufficient to visualize novel features, including choriocapillaris morphology beneath the macula and macrophage-like cells at the inner limiting membrane, both of which may have implications for disease.
Subject(s)
Diabetic Retinopathy , Retinal Vessels , Humans , Retinal Vessels/pathology , Fluorescein Angiography , Tomography, Optical Coherence/methods , RetinaABSTRACT
High-quality swept-source optical coherence tomography (SS-OCT) requires accurate k-sampling, which is equally vital for optical coherence tomography angiography (OCTA). Most SS-OCT systems are equipped with hardware-driven k-sampling. However, this conventional approach raises concerns over system cost, optical alignment, imaging depth, and stability in the clocking circuit. This work introduces an optimized numerical k-sampling method to replace the additional k-clock hardware. Using this method, we can realize high axial resolution (4.9-µm full-width-half-maximum, in air) and low roll-off (2.3â dB loss) over a 4-mm imaging depth. The high axial resolution and sensitivity achieved by this simple numerical method can reveal anatomic and microvascular structures with structural OCT and OCTA in both macular and deeper tissues, including the lamina cribrosa, suggesting its usefulness in imaging retinopathy and optic neuropathy.
Subject(s)
Angiography , Tomography, Optical Coherence , Tomography, Optical Coherence/methods , Fluorescein Angiography/methodsABSTRACT
Autism is often comorbid with other psychiatric disorders. We have previously shown that Dip2a knockout (KO) induces autism-like behaviors in mice. However, the role of Dip2a in other psychiatric disorders remains unclear. In this paper, we revealed that Dip2a KO mice had comorbid anxiety. Dip2a KO led to a reduction in the dendritic length of cortical and hippocampal excitatory neurons. Molecular mechanism studies suggested that AMPK was overactivated and suppressed the mTOR cascade, contributing to defects in dendritic morphology. Deletion of Dip2a in adult-born hippocampal neurons (Dip2a conditional knockout (cKO)) increased susceptibility to anxiety upon acute stress exposure. Application of (2R,6R)-hydroxynorketamine (HNK), an inhibitor of mTOR, rescued anxiety-like behaviors in Dip2a KO and Dip2a cKO mice. In addition, 6 weeks of high-fat diet intake alleviated AMPK-mTOR signaling and attenuated the severity of anxiety in both Dip2a KO mice and Dip2a cKO mice. Taken together, these results reveal an unrecognized function of DIP2A in anxiety pathophysiology via regulation of AMPK-mTOR signaling.
Subject(s)
AMP-Activated Protein Kinases , Signal Transduction , Mice , Animals , Mice, Knockout , TOR Serine-Threonine Kinases/metabolism , Anxiety/genetics , Nuclear ProteinsABSTRACT
OBJECTIVE: This study aimed to evaluate the yield and applicability of expanded carrier screening and propose carrier rate screening thresholds suitable for the Chinese population by comparing the current screening panel with the American College of Medical Genetics and Genomics recommended panel of 113 genes. METHODS: Using targeted next-generation sequencing, a customized panel with 334 genes was performed on 2168 individuals without clinical phenotypes for expanded carrier screening purpose. Variant interpretation followed the American College of Medical Genetics and Genomics guidelines. Carrier rates were calculated for each identified variant and each gene. At-risk couple rates were also assessed. The yield of expanded carrier screening was evaluated through calculating cumulative carrier rate. RESULTS: Overall, 65.87% of the individuals were found to be carriers of at least 1 disease causing variants. The overall at-risk couple rate was 11.76%, of which the GJB2:c.109G > A related at-risk couple rate was 5.78%. The cumulative carrier rate of 334-panel was 65.53%. When screened genes with gene carrier rate ≥1/1000, the expanded carrier screening can cover over 90% of the cumulative carrier rate and at-risk couples. A total of 86 genes overlapped with American College of Medical Genetics and Genomics Tier-3 genes and were attributed to the cumulative carrier rate of 47.33%. CONCLUSION: Expanded carrier screening using the 334-gene panel showed high screening efficiency. A threshold of gene carrier rate ≥1/1000 is recommended for selecting carrier screening genes in the Chinese Han population. This study highlights the importance of customizing screening panels based on the ACMG Tier-3 genes in conjunction with population-specific carrier frequencies to improve the accuracy and effectiveness of expanded carrier screening.
ABSTRACT
HYPOTHESIS: Our study investigates the reliability of deltoid tuberosity index (DTI) and DTI as a predictor of systemic osteoporosis. BACKGROUND: The proximal humerus is a common fragility fracture. Current literature suggests that poor local bone density is a significant predictor for surgical fixation failure. The DTI is a simple radiographical tool that is strongly correlates with local humeral BMD aiding surgical planning to consider adjuncts or arthroplasty. However, there is a lack of data in the reliability of assessment of DTI, as well as its correlation to systemic osteoporosis. METHODS: Respective cohort of patients with PHF treated at a trauma center in Singapore from August 2017 to July 2018 were recruited. Four raters at different levels of varying clinical seniority measured DTI using shoulder radiographs. The dual energy X-ray Absorptiometry (DEXA) bone mineral density (BMD) scan of the hip and lumbar spine was used to diagnose osteoporosis. Area under receiver operating characteristics (AUROC) analysis was conducted to study the diagnostic utility of DTI to predict the risk of osteoporosis. RESULTS: Our study had 87 patients consisting 18 males and 69 females, mainly of Chinese ethnicity (84%) and mean age of 69.7 years (SD 9.52, range 39-92yrs). For assessment of DTI, there was good intra-rater reliability amongst four raters (correlation coefficient range 0.805- 0.843) and excellent inter-rater reliability between al raters (intraclass correlation coefficient = 0.898; 95% CI 0.784-0.950, p-value <0.001). Based on BMD, 55.2% (n=48) were osteoporotic using T-score <-2.5. The highest correlation of DTI to BMD was with femoral neck density at 0.580. The DTI cut-off of 1.6 had the highest combined sensitivity and false positive rate, with area under curve (AUC) = 0.682 (95% CI, 0.564-0.799) for the overall population and AUC =0.706 (95% CI, 0.569-0.842) for patients <75 years. DISCUSSION: The DTI is a simple and reliable tool, strengthening its applicability in clinical practice to enhance preoperative planning in the surgical fixation of PHF. DTI with a cut off of 1.6 may be helpful tool prompting clinicians to workup and manage underlying osteoporosis.
ABSTRACT
Recycling of carbon fiber-reinforced polymer composites (CFRCs) based on thermosetting plastics is difficult. In the present study, high-performance CFRCs are fabricated through complexation of aromatic pinacol-cross-linked polyurethane (PU-AP) thermosets with carbon fiber (CF) cloths. PU-AP thermosets exhibit a breaking strength of 95.5â MPa and toughness of 473.6â MJ m-3 and contain abundant hydrogen-bonding groups, which can have strong adhesion with CFs. Because of the high interfacial adhesion between CF cloths and PU-AP thermosets and high toughness of PU-AP thermosets, CF/PU-AP composites possess a high tensile strength of >870â MPa. Upon heating in N,N-dimethylacetamide (DMAc) at 100 °C, the aromatic pinacols in the CF/PU-AP composites can be cleaved, generating non-destructive CF cloths and linear polymers that can be converted to high-performance elastomers. The elastomers are mechanically robust, healable, reprocessable, and damage-resistant with an extremely high tensile strength of 74.2â MPa and fracture energy of 149.6â kJ m-2. As a result, dissociation of CF/PU-AP composites enables the recovery of reusable CF cloths and high-performance elastomers, thus realizing the upcycling of CF/PU-AP composites.
ABSTRACT
BACKGROUND: Mitochondrial dysfunction of macrophage-mediated inflammatory response plays a key pathophysiological process in myocardial infarction (MI). Calpains are a well-known family of calcium-dependent cysteine proteases that regulate a variety of processes, including cell adhesion, proliferation, and migration, as well as mitochondrial function and inflammation. CAPNS1, the common regulatory subunit of calpain-1 and 2, is essential for the stabilization and activity of the catalytic subunit. Emerging studies suggest that calpains may serve as key mediators in mitochondria and NLRP3 inflammasome. This study investigated the role of myeloid cell calpains in MI. METHODS: MI models were constructed using myeloid-specific Capns1 knockout mice. Cardiac function, cardiac fibrosis, and inflammatory infiltration were investigated. In vitro, bone marrow-derived macrophages (BMDMs) were isolated from mice. Mitochondrial function and NLRP3 activation were assessed in BMDMs under LPS stimulation. ATP5A1 knockdown and Capns1 knock-out mice were subjected to MI to investigate their roles in MI injury. RESULTS: Ablation of calpain activities by Capns1 deletion improved the cardiac function, reduced infarct size, and alleviated cardiac fibrosis in mice subjected to MI. Mechanistically, Capns1 knockout reduced the cleavage of ATP5A1 and restored the mitochondria function thus inhibiting the inflammasome activation. ATP5A1 knockdown antagonized the protective effect of Capns1 mKO and aggravated MI injury. CONCLUSION: This study demonstrated that Capns1 depletion in macrophages mitigates MI injury via maintaining mitochondrial homeostasis and inactivating the NLRP3 inflammasome signaling pathway. This study may offer novel insights into MI injury treatment.
ABSTRACT
Self-incompatibility (SI) is a reproductive protection mechanism that plants acquired during evolution to prevent self-recession. As the female determinant of SI specificity, SRK has been shown to be the only recognized gene on the stigma and plays important roles in SI response. Asteraceae is the largest family of dicotyledonous plants, many of which exhibit self-incompatibility. However, systematic studies on SRK gene family in Asteraceae are still limited due to lack of high-quality genomic data. In this study, we performed the first systematic genome-wide identification of S-locus receptor like kinases (SRLKs) in the self-incompatible Asteraceae species, Erigeron breviscapus, which is also a widely used perennial medicinal plant endemic to China.52 SRLK genes were identified in the E. breviscapus genome. Structural analysis revealed that the EbSRLK proteins in E. breviscapus are conserved. SRLK proteins from E. breviscapus and other SI plants are clustered into 7 clades, and the majority of the EbSRLK proteins are distributed in Clade I. Chromosomal and duplication analyses indicate that 65% of the EbSRLK genes belong to tandem repeats and could be divided into six tandem gene clusters. Gene expression patterns obtained in E. breviscapus multiple-tissue RNA-Seq data revealed differential temporal and spatial features of EbSRLK genes. Among these, two EbSRLK genes having high expression levels in tongue flowers were cloned. Subcellular localization assay demonstrated that both of their fused proteins are localized on the plasma membrane. All these results indicated that EbSRLK genes possibly involved in SI response in E. breviscapus. This comprehensive genome-wide study of the SRLK gene family in E. breviscapus provides valuable information for understanding the mechanism of SSI in Asteraceae.
Subject(s)
Erigeron , Erigeron/genetics , Erigeron/metabolism , Genome-Wide Association Study , Plant Proteins/metabolism , Flowers/genetics , Flowers/metabolism , ChinaABSTRACT
BACKGROUND: E1A-associated 300-kDa protein (P300), an endogenous histone acetyltransferase, contributes to modifications of the chromatin landscape of genes involved in multiple cardiovascular diseases. Ferroptosis of vascular smooth muscle cells (VSMCs) is a novel pathological mechanism of aortic dissection. However, whether P300 regulates VSMC ferroptosis remains unknown. METHODS: Cystine deprivation (CD) and imidazole ketone erastin (IKE) were used to induce VSMC ferroptosis. Two different knockdown plasmids targeting P300 and A-485 (a specific inhibitor of P300) were used to investigate the function of P300 in the ferroptosis of human aortic smooth muscle cells (HASMCs). Cell counting kit-8, lactate dehydrogenase and flow cytometry with propidium iodide staining were performed to assess the cell viability and death under the treatment of CD and IKE. BODIPY-C11 assay, immunofluorescence staining of 4-hydroxynonenal and malondialdehyde assay were conducted to detect the level of lipid peroxidation. Furthermore, co-immunoprecipitation was utilized to explore the interaction between P300 and HIF-1α, HIF-1α and P53. RESULTS: Compared with normal control, the protein level of P300 was significantly decreased in HASMCs treated with CD and IKE, which was largely nullified by the ferroptosis inhibitor ferrostatin-1 but not by the autophagy inhibitor or apoptosis inhibitor. Knockdown of P300 by short-hairpin RNA or inhibition of P300 activity by A-485 promoted CD- and IKE-induced HASMC ferroptosis, as evidenced by a reduction in cell viability and aggravation of lipid peroxidation of HASMCs. Furthermore, we found that hypoxia-inducible factor-1α (HIF-1α)/heme oxygenase 1 (HMOX1) pathway was responsible for the impacts of P300 on ferroptosis of HASMCs. The results of co-immunoprecipitation demonstrated that P300 and P53 competitively bound HIF-1α to regulate the expression of HMOX1. Under normal conditions, P300 interacted with HIF-1α to inhibit HMOX1 expression, while reduced expression of P300 induced by ferroptosis inducers would favor HIF-1α binding to P53 to trigger HMOX1 overexpression. Furthermore, the aggravated effects of P300 knockdown on HASMC ferroptosis were largely nullified by HIF-1α knockdown or the HIF-1α inhibitor BAY87-2243. CONCLUSION: Thus, our results revealed that P300 deficiency or inactivation facilitated CD- and IKE-induced VSMC ferroptosis by activating the HIF-1α/HMOX1 axis, which may contribute to the development of diseases related to VSMC ferroptosis.
Subject(s)
Ferroptosis , Muscle, Smooth, Vascular , Humans , Heme Oxygenase-1/genetics , Heme Oxygenase-1/metabolism , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Muscle, Smooth, Vascular/metabolism , Myocytes, Smooth Muscle/metabolism , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolismABSTRACT
Transmission of sub-terahertz (sub-THz) signals over a fiber-free-space optical (FSO)-fifth-generation (5â G) new radio (NR) hybrid system is successfully realized. It is a promising system that utilizes multiple media of optical fiber, optical wireless, and 5â G NR wireless to achieve a 227.912-Gb/s record-high aggregate net bit rate. The system concurrently transmits a 59.813-Gb/s net bit rate in the 150-GHz sub-THz frequency, 74.766-Gb/s in the 250-GHz sub-THz frequency, and 93.333-Gb/s in the 325-GHz sub-THz frequency through the fiber-FSO-wireless convergence, including 25-km single-mode fiber, 100-m FSO, and 30-m/25-m/20-m sub-THz-wave transmissions. This system achieves sufficiently low bit error rates (< hard-decision forward error correction (FEC) threshold of 3.8 × 10-3 at 16 and 20 Gbaud symbol rates; < soft-decision FEC threshold of 2 × 10-2 at 28 Gbaud symbol rate) and clear and distinct constellation diagrams, meeting the demands of 5â G NR communications in the sub-THz band. The development of fiber-FSO-5â G NR hybrid system represents a substantial development in the field of advanced communications. It has the ability to enhance the way we communicate in the future.
ABSTRACT
Autophagy plays an important role in plant-pathogen interactions. Several pathogens including viruses induce autophagy in plants, but the underpinning mechanism remains largely unclear. Furthermore, in virus-plant interactions, viral factor(s) that induce autophagy have yet to be identified. Here, we report that the ßC1 protein of Cotton leaf curl Multan betasatellite (CLCuMuB) interacts with cytosolic glyceraldehyde-3-phosphate dehydrogenase (GAPC), a negative autophagic regulator, to induce autophagy in Nicotiana benthamiana CLCuMuB ßC1 bound to GAPCs and disrupted the interaction between GAPCs and autophagy-related protein 3 (ATG3). A mutant ßC1 protein (ßC13A) in which I45, Y48, and I53 were all substituted with Ala (A), had a dramatically reduced binding capacity with GAPCs, failed to disrupt the GAPCs-ATG3 interactions and failed to induce autophagy. Furthermore, mutant virus carrying ßC13A showed increased symptoms and viral DNA accumulation associated with decreased autophagy in plants. These results suggest that CLCuMuB ßC1 activates autophagy by disrupting GAPCs-ATG3 interactions.
Subject(s)
Autophagy-Related Proteins/metabolism , Autophagy , Begomovirus/metabolism , Glyceraldehyde-3-Phosphate Dehydrogenases/metabolism , Nicotiana/metabolism , Nicotiana/virology , Plant Proteins/metabolism , Viral Proteins/metabolism , Protein Binding , Nicotiana/ultrastructure , Vacuoles/metabolism , Vacuoles/ultrastructureABSTRACT
Background: Some patients with hypertrophic obstructive cardiomyopathy (HOCM) still exhibit systolic anterior motion (SAM) and mitral regurgitation (MR) even after undergoing an isolated ventricular septectomy. Currently, there are disputes regarding whether to perform a mitral valve intervention and which type of operation is more effective. Methods: By searching PubMed, Cochrane, Embase, Web of Science, FDA.gov, and ClinicalTrials.gov, as well as other resource databases, we obtained all articles published before December 2022 on ventricular septal myectomy combined with mitral valve intervention for hypertrophic cardiomyopathy. Demographic information and outcome variable data were extracted from 10 screened studies on ventricular septal resection combined with mitral valve repair. The risk of bias was assessed using methodological index for non-randomized studies (MINORS). Student's t-test was used for comparisons of continuous variables, and the chi-square or Fisher's exact test was used for dichotomous variables. A total of 692 patients across 10 studies were analyzed. Results: There were 5 (0.7%) deaths in the perioperative period. The average cardiopulmonary bypass time was 64.7 ± 22.2 minutes, and the average follow-up time was 39.6 ± 36.3 months. Compared with baseline levels, the left ventricular outflow tract gradient (83.6 ± 32.2 mmHg vs. 11.0 ± 7.8 mmHg, p < 0.01), maximum interventricular septal thickness (22.5 ± 5.1 mm vs. 14.7 ± 5.5 mm, p < 0.01), III/IV mitral regurgitation (351/692 vs. 17/675, p < 0.01), anterior mitral leaflet (AML)-annulus ratio (0.49 ± 0.14 vs. 0.60 ± 0.12, p < 0.01), tenting area (2.72 ± 0.60 cm 2 vs. 1.95 ± 0.60 cm 2 , p < 0.01), and SAM (181/194 vs. 11/215, p < 0.01) were significantly improved. 14 (2.1%) patients were in New York Heart Association functional class III/IV, which was significantly improved compared with the preoperative state (541/692 vs. 14/682, p < 0.01). Conclusions: Ventricular septectomy combined with mitral valve repair can be a safe and effective treatment option for patients suffering from HOCM with SAM and severe MR.