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"Zhu, Jianhua"
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Novel plant-derived exosome-like nanovesicles from Catharanthus roseus: preparation, characterization, and immunostimulatory effect via TNF-α/NF-κB/PU.1 axis
Background
Plant-derived exosomes-like nanovesicles (PDENs) have been found to be advantageous in disease treatment and drug delivery, but research on their biogenesis, compositional analysis, and key marker proteins is still in its infancy, which limits the standardized production of PDENs. Efficient preparation of PDENs continues to be a major challenge.
Results
Novel PDENs-based chemotherapeutic immune modulators,
Catharanthus roseus
(L.) Don leaves-derived exosome-like nanovesicles (CLDENs) were isolated from apoplastic fluid. CLDENs were membrane structured vesicles with a particle size of 75.51 ± 10.19 nm and a surface charge of −21.8 mV. CLDENs exhibited excellent stability, tolerating multiple enzymatic digestions, resisting extreme pH environments, and remaining stable in the gastrointestinal simulating fluid. Biodistribution experiments showed that CLDENs could be internalized by immune cells, and targeted at immune organs after intraperitoneal injection. The lipidomic analysis revealed CLDENs’ special lipid composition, which contained 36.5% ether-phospholipids. Differential proteomics supported the origin of CLDENs in multivesicular bodies, and six marker proteins of CLDENs were identified for the first time. 60 ~ 240 μg/ml of CLDENs promoted the polarization and phagocytosis of macrophages as well as lymphocyte proliferation in vitro. Administration of 20 mg/kg and 60 mg/kg of CLDENs alleviated white blood cell reduction and bone marrow cell cycle arrest in immunosuppressive mice induced by cyclophosphamide. CLDENs strongly stimulated the secretion of TNF-α, activated NF-κB signal pathway and increased the expression of the hematopoietic function-related transcription factor PU.1 both in vitro and in vivo. To ensure a steady supply of CLDENs, plant cell culture systems of
C. roseus
were established to provide CLDENs-like nanovesicles which had similar physical properties and biological activities. Gram-level nanovesicles were successfully obtained from the culture medium, and the yield was three times as high as the original.
Conclusions
Our research supports the use of CLDENs as a nano-biomaterial with excellent stability and biocompatibility, and for post-chemotherapy immune adjuvant therapy applications.
Graphical Abstract
Journal Article
The Protein Phosphatase RCF2 and Its Interacting Partner NAC019 Are Critical for Heat Stress-Responsive Gene Regulation and Thermotolerance in Arabidopsis
Heat stress is a major environmental constraint for crop production worldwide. To respond to and cope with heat stress, plants synthesize heat shock proteins (HSPs), which are often molecular chaperones and are under the control of heat stress transcription factors (HSFs). Very little is known about the upstream regulators of HSFs. In a forward genetic screen for regulators of C-REPEAT BINDING FACTOR (CBF) gene expression (RCFs), we identified RCF2 and found that it is allelic to CPL1/FIERY2, which encodes a homolog of C-terminal domain phosphatase. Our results also showed that, in addition to being critical for cold stress tolerance, RCF2 is required for heat stress-responsive gene regulation and thermotolerance, because, compared with the wild type, the rcf2-1 mutant is hypersensitive to heat stress and because the reduced thermotolerance is correlated with lower expression of most of the 21 HSFs and some of the HSPs in the mutant plants. We found that RCF2 interacts with the NAC transcription factor NAC019 and that RCF2 dephosphorylates NAC019 in vivo. The nac019 mutant is more sensitive to heat stress than the wild type, and chromatin immunoprecipitation followed by quantitative PCR analysis revealed that NAC019 binds to the promoters of HSFA1b, HSFA6b, HSFA7a, and HSFC1. Overexpression of RCF2 or NAC019 in Arabidopsis thaliana increases thermotolerance. Together, our results suggest that, through dephosphorylation of NAC019, RCF2 is an integrator of high-temperature signal transduction and a mechanism for HSF and HSP activation.
Journal Article
An atypical R2R3 MYB transcription factor increases cold hardiness by CBF-dependent and CBF-independent pathways in apple
Apple (Malus × domestica) trees are vulnerable to freezing temperatures. However, there has been only limited success in developing cold-hardy cultivars. This lack of progress is due at least partly to lack of understanding of the molecular mechanisms of freezing tolerance in apple.
In this study, we evaluated the potential roles for two R2R3 MYB transcription factors (TFs), MYB88 and the paralogous FLP (MYB124), in cold stress in apple and Arabidopsis. We found that MYB88 and MYB124 positively regulate freezing tolerance and cold-responsive gene expression in both apple and Arabidopsis.
Chromatin-Immunoprecipitation-qPCR and electrophoretic mobility shift assays showed that MdMYB88/MdMYB124 act as direct regulators of the COLD SHOCK DOMAIN PROTEIN 3 (MdCSP3) and CIRCADIAN CLOCK ASSOCIATED 1 (MdCCA1) genes. Dual luciferase reporter assay indicated that MdCCA1 but not MdCSP3 activated the expression of MdCBF3 under cold stress. Moreover, MdMYB88 and MdMYB124 promoted anthocyanin accumulation and H2O2 detoxification in response to cold.
Taken together, our results suggest that MdMYB88 and MdMYB124 positively regulate cold hardiness and cold-responsive gene expression under cold stress by C-REPEAT BINDING FACTOR (CBF)-dependent and CBF-independent pathways.
Journal Article
Beyond Compliance: How Disruptive Innovation Unleashes ESG Value Under Digital Institutional Pressure
Amid intensifying global ESG regulations and the expanding influence of green finance, China’s digital economy policies have emerged as key institutional instruments for promoting corporate sustainability. Leveraging the implementation of the National Big Data Comprehensive Pilot Zone as a quasi-natural experiment, this study utilizes panel data of Chinese listed firms from 2009 to 2023 and applies multi-period Difference-in-Differences (DID) and Spatial DID models to rigorously identify the policy’s effects on corporate ESG performance. Empirical results indicate that the impact of digital economy policy is not exerted through a direct linear pathway but operates via three institutional mechanisms, enhanced information transparency, eased financing constraints, and expanded fiscal support, collectively constructing a logic of “institutional embedding–governance restructuring.” Moreover, disruptive technological innovation significantly amplifies the effects of the transparency and fiscal mechanisms, but exhibits no statistically significant moderating effect on the financing constraint pathway, suggesting a misalignment between innovation heterogeneity and financial responsiveness. Further heterogeneity analysis confirms that the policy effect is concentrated among firms characterized by robust governance structures, high levels of property rights marketization, and greater digital maturity. This study contributes to the literature by developing an integrated moderated mediation framework rooted in institutional theory, agency theory, and dynamic capabilities theory. The findings advance the theoretical understanding of ESG policy transmission by unpacking the micro-foundations of institutional response under digital policy regimes, while offering actionable insights into the strategic alignment of digital transformation and sustainability-oriented governance.
Journal Article
Urbanization Intensifies the Mismatch between the Supply and Demand of Regional Ecosystem Services: A Large-Scale Case of the Yangtze River Economic Belt in China
The process of rapid urbanization has been causing non-negligible disturbances to our ecosystems, which has aggravated the mismatch between ecosystem service (ES) supply and demand. A clear understanding of the relationship between the ES supply–demand mismatch and urbanization is crucial as it could have a lot of significance for implementing ecological compensation and conservation action. Although a large number of studies have explored this problem, previous studies have focused primarily on the spatial mismatching of the ESs, and only a few studies have considered the spatial relationship between the ES supply–demand mismatch and urbanization at the watershed scale. Taking the Yangtze River Economic Belt (YREB) as an example, this study quantitatively assesses the supply and demand of five ESs, including carbon sequestration, water retention, soil conservation, food production, and recreational opportunity. The bivariate Moran’s I method was used to analyze and visualize the spatial correlation between the ES supply–demand mismatch and urbanization. The results indicate that both the total supply and the total demand of the five ESs increased, while the increasing rate of total demand was higher than the total supply of the ESs; this resulted in a significant spatial mismatch between the supply and demand of the ESs from 2000 to 2020. There is also a negative spatial correlation between the ES supply–demand and urbanization, while the results of local spatial clustering have obvious spatial heterogeneity. The metropolis and its surrounding counties are mostly the ES supply and demand deficit area, but some surrounding counties have managed to transform a deficit into a surplus. These results indicate that urbanization has a certain interference on the mismatch of the ES supply and demand, and this interference is not irreversible. Moreover, this study provides a reliable reference for government management in the context of balancing urbanization and the ecosystem.
Journal Article
The Arabidopsis NFYA5 Transcription Factor Is Regulated Transcriptionally and Posttranscriptionally to Promote Drought Resistance
Nuclear factor Y (NF-Y) is a ubiquitous transcription factor composed of three distinct subunits (NF-YA, NF-YB, and NF-YC). We found that the Arabidopsis thaliana NFYA5 transcript is strongly induced by drought stress in an abscisic acid (ABA)-dependent manner. Promoter:β-glucuronidase analyses showed that NFYA5 was highly expressed in vascular tissues and guard cells and that part of the induction by drought was transcriptional. NFYA5 contains a target site for miR169, which targets mRNAs for cleavage or translational repression. We found that miR169 was downregulated by drought stress through an ABA-dependent pathway. Analysis of the expression of miR169 precursors showed that miR169a and miR169c were substantially downregulated by drought stress. Coexpression of miR169 and NFYA5 suggested that miR169a was more efficient than miR169c at repressing the NFYA5 mRNA level. nfya5 knockout plants and plants overexpressing miR169a showed enhanced leaf water loss and were more sensitive to drought stress than wild-type plants. By contrast, transgenic Arabidopsis plants overexpressing NFYA5 displayed reduced leaf water loss and were more resistant to drought stress than the wild type. Microarray analysis indicated that NFYA5 is crucial for the expression of a number of drought stress-responsive genes. Thus, NFYA5 is important for drought resistance, and its induction by drought stress occurs at both the transcriptional and posttranscriptional levels.
Journal Article
An Efficient YOLO Algorithm with an Attention Mechanism for Vision-Based Defect Inspection Deployed on FPGA
Industry 4.0 features intelligent manufacturing. Among them, the vision-based defect inspection algorithm is remarkable for quality control in parts manufacturing. With the help of AI and machine learning, auto-adaptive instead of manual operation is achievable in this field, and much progress has been made in recent years. In this study, considering the demand of inspection features in industrialization, we made further improvement in smart defect inspection. An efficient algorithm using Field Programmable Gate Array (FPGA)-accelerated You Only Look Once (YOLO) v3 based on an attention mechanism is proposed. First, because of the relatively fixed camera angle and defect features, an attention mechanism based on the concept of directing the focus of defect inspection is proposed. The attention mechanism consists of three improvements: (a) image preprocessing, which is to tailor images for selectively concentrating on the defect relevant things. Image preprocessing mainly includes cutting, zooming and splicing, named CZS operations. (b) Tailoring the YOLOv3 backbone network, which is to ignore invalid inspection regions in deep neural networks and optimize the network structure. (c) Data augmentation. First, two improvements can be made to efficiently reduce deep learning operations and accelerate the inspection speed, but the preprocessed images are similar and the lack of diversity will reduce network accuracy. So, (c) is added to mitigate the lack of considerable amounts of training data. Second, the algorithm is deployed on a PYNQ-Z2 FPGA board to meet the industrialization production requirements for accuracy, efficiency and extensibility. FPGA can provide a low-latency, low-cost, high-power-efficiency and flexible architecture that enables deep learning acceleration for industrial scenarios. A Xilinx Deep Neural Network Development Kit (DNNDK) converted the improved YOLOv3 to Programmable Logic (PL), which can be deployed on FPGA. The conversion process mainly consists of pruning, quantization and compilation. Experimental results showed that the algorithm had high efficiency, inspection accuracy reached 99.2%, processing speed reached 1.54 Frames per Second (FPS), and power consumption was only 10 W.
Journal Article
Dihydroartemisinic acid dehydrogenase-mediated alternative route for artemisinin biosynthesis
Dihydroartemisinic acid (DHAA) converts into antimalarial drug artemisinin (ART) by auto-oxidation. High production of artemisinic acid (AA) has been achieved by fermentation of engineered
Saccharomyces cerevisiae
, and AA can be converted into ART through DHAA by chemical synthesis. However, there is no enzyme reported to catalyze the conversion of AA to DHAA. Here, we report a dihydroartemisinic acid dehydrogenase (
Aa
DHAADH) from
Artemisia annua
L, which catalyzes the bidirectional conversion between AA and DHAA. An optimized mutant
Aa
DHAADH (P26L) is obtained through site-directed mutagenesis and its activity toward AA is 2.82 times that of the original gene. De novo synthesis of DHAA is achieved in
S. cerevisiae
using the targeted optimized gene
AaDHAADH (P26L)
. Furthermore, 3.97 g/L of DHAA is obtained by fermentation of engineered
S. cerevisiae
in 5 L bioreactor. The discovery of
Aa
DHAADH provides a more convenient and efficient alternative route for ART biosynthesis.
Semi-synthesis of artemisinin has been achieved by autooxidation of dihydroartemisinic acid (DHAA), but DHAA supply relies on chemical synthesis from artemisinic acid. Here, authors report the identification of dihydroartemisinic acid dehydrogenase from
Artemisia annua
and its engineering for DHAA bioproduction in yeast.
Journal Article
Exploring Single-Molecular Magnets for Quantum Technologies
A single-molecule magnet (SMM) is a molecule that functions as a magnet. SMMs can be explored not only for emerging technology but also the fundamental science of their quantum nature, nanometer sizes, and their ease of engineering. This review encompasses the state-of-the-art experiments and theories developed so far for SMMs. We briefly explore their experimental synthesis and characterization. In the experimental synthesis, we cover ‘Click Chemistry’ and supramolecular chemistry. The main experimental characterizations comprise superconducting quantum interference devices, electron paramagnetic resonance, neutron scattering, and X-ray magnetic circular dichroism. The theoretical and computational works based on the density functional theory, the post-Hartree–Fock methods, and the theory of open quantum systems are discussed. Moreover, we exemplify the numerous promising research areas for SMMs by discussing quantum technologies. We envision a brilliant future for the fundamental research and emerging applications of SMMs.
Journal Article