NLRP3 promotes radiation-induced brain injury by regulating microglial pyroptosis.

PURPOSE: Radiation-induced brain injury, one of the side effects of cranial radiotherapy in tumour patients, usually results in durable and serious cognitive disorders. Microglia are important innate immune-effector cells in the central nervous system. However, the interaction between microglia and neurons in radiation-induced brain injury remains uncharacterised. METHODS AND MATERIALS: We established a microglia-neuron indirect co-culture model to assess the interaction between them. Microglia exposed to radiation were examined for pyroptosis using lactate dehydrogenase (LDH) release, Annexin V/PI staining, SYTOX staining and western blot. The role of nucleotide-binding oligomerisation domain-like receptor family pyrin domain containing 3 (NLRP3) was investigated in microglia exposed to radiation and in mouse radiation brain injury model through siRNA or inhibitor. Mini-mental state examination and cytokines in blood were performed in 23 patients who had experienced cranial irradiation. RESULTS: Microglia exerted neurotoxic features after radiation in the co-culture model. NLRP3 was up-regulated in microglia exposed to radiation, and then caspase-1 was activated. Thus, the gasdermin D protein was cleaved, and it triggered pyroptosis in microglia, which released inflammatory cytokines. Meanwhile, treatment with siRNA NLRP3 in vitro and NLRP3 inhibitor in vivo attenuated the damaged neuron cell and cognitive impairment, respectively. What is more, we found that the patients after radiation with higher IL-6 were observed to have a decreased MMSE score. CONCLUSIONS: These findings indicate that radiation-induced pyroptosis in microglia may promote radiation-induced brain injury via the secretion of neurotoxic cytokines. NLRP3 was evaluated as an important mediator in radiation-induced pyroptosis and a promising therapeutic target for radiation-induced brain injury.

Periodontitis promotes the progression of diabetes mellitus by enhancing autophagy.

Objective: This study aims to identify the periodontitis factor that activates excessive autophagy in pancreatic ß cells, resulting in organic lesions of pancreatic islet tissues and diminished insulin secretion, thereby accelerating the progression of diabetes mellitus (DM). Methods: Sprague-Dawley (SD) rats were induced with periodontitis (PD), type 2 diabetes mellitus (T2DM), or the combination of T2DM and PD (DP) through a high-sugar/high-fat diet and ligation of the tooth neck with silk thread. Alveolar bone resorption was assessed using Micro-CT, blood glucose levels were measured with a blood glucose meter, pancreatic tissue pathology was examined through HE staining, and the expression of autophagy-related proteins Beclin1 and LC3II/LC3I was analyzed using Western blotting. Results: Micro-CT results revealed more pronounced alveolar bone resorption and root bifurcation exposure in the PD and DP groups compared to the control group, with the DP group exhibiting the most severe condition. HE staining demonstrated the formation of periodontal pockets, severe alveolar bone destruction, and abnormal pancreatic islet tissue morphology in the PD and DP groups. The serum levels of IL-6, TNF-α, and IL-1ß increased sequentially in the control, DM, PD, and DP groups (P < 0.05). Relative expressions of GCK and GLUT-2 mRNA decreased in the PD group compared to the control group (P > 0.05), while the mRNA expressions in the DP and DM groups increased (P < 0.05), with the DP group exhibiting higher levels than the DM group (P < 0.05). Western blot results indicated increased expression levels of autophagy proteins Beclin1 and LC3II/LC3I in the DM and DP groups compared to the control group (P < 0.05), with the DP group exhibiting higher levels than the DM group (P < 0.05). Conclusion: The findings demonstrate that periodontal inflammatory factors may promote the enhancement of pancreatic cell autophagy in diabetic rats.

Prognostic Analysis of a Hypoxia-Associated lncRNA Signature in Glioblastoma and its Pan-Cancer Landscape.

BACKGROUND: Hypoxia is an important clinical feature of glioblastoma (GBM), which regulates a variety of tumor processes and is inseparable from radiotherapy. Accumulating evidence suggests that long noncoding RNAs (lncRNAs) are strongly associated with survival outcomes in GBM patients and modulate hypoxia-induced tumor processes. Therefore, the aim of this study was to establish a hypoxia-associated lncRNAs (HALs) prognostic model to predict survival outcomes in GBM patients. METHODS: LncRNAs in GBM samples were extracted from The Cancer Genome Atlas database. Hypoxia-related genes were downloaded from the Molecular Signature Database. Co-expression analysis of differentially expressed lncRNAs and hypoxia-related genes in GBM samples was performed to determine HALs. Six optimal lncRNAs were selected for building HALs models by univariate Cox regression analysis. RESULTS: The prediction model has a good predictive effect on the prognosis of GBM patients. Meanwhile, LINC00957 among the six lncRNAs was selected and subjected to pan-cancer landscape analysis. CONCLUSION: Taken together, our findings suggest that the HALs assessment model can be used to predict the prognosis of GBM patients. In addition, LINC00957 included in the model may be a useful target to study the mechanism of cancer development and design individualized treatment strategies.

Who would rescue the dilemma of Chinese elderly care? An evolutionary game analysis and simulation research on the formalization of the domestic service industry with subsidy policy.

Since China entered the aging society, the surging demand for elderly care and the industrial upgrading of "silver economy" has forced the domestic service industry to face endogenous challenges. Among them, the formalization of the domestic service industry can effectively reduce the transaction costs and risks of actors, innovate the endogenous vitality of the industry, and promote the improvement of elderly care quality through a triangular employment relationship. By constructing a tripartite asymmetric evolutionary game model of clients, domestic enterprises and governmental departments, this study uses the stability theorem of differential equations to explore the influencing factors and action paths of the system's evolutionary stable strategies (ESS), and uses the research data collected from China to assign values to models for simulation analysis. This study finds that the ratio of the initial ideal strategy, the difference between profits and costs, subsidies to clients, and subsidies or punishments for breach of contract to domestic enterprises are the key factors affecting the formalization of the domestic service industry. Subsidy policy programs can be divided into long-term and periodic programs, and there are differences in the influence paths and effects of the key factors in different situations. Increasing domestic enterprises' market share with employee management systems, formulating subsidy programs for clients, and setting up evaluation and supervision mechanisms are efficient ways through which to promote the formalization of the domestic service industry in China. Subsidy policy of governmental departments should focus on improving the professional skills and quality of elderly care domestic workers, and also encourage domestic enterprises with employee management systems at the same time, to expand the scope of service beneficiaries by running nutrition restaurants in communities, cooperating with elderly care institutions, etc.

Melatonin reduces radiation-induced ferroptosis in hippocampal neurons by activating the PKM2/NRF2/GPX4 signaling pathway.

Ferroptosis is a type of regulated cell death that is dependent on iron and reactive oxygen species (ROS). Melatonin (N-acetyl-5-methoxytryptamine) reduces hypoxic-ischemic brain damage via mechanisms that involve free radical scavenging. How melatonin regulates radiation-induced ferroptosis of hippocampal neurons is yet to be elucidated. In this study, the mouse hippocampal neuronal cell line HT-22 was treated with 20µM melatonin before being stimulated with a combination of irradiation and 100 µM FeCl3. Furthermore, in vivo experiments were performed in mice treated with melatonin via intraperitoneal injection, which was followed by radiation exposure. A series of functional assays, including CCK-8, DCFH-DA kit, flow cytometry, TUNEL staining, iron estimations, and transmission electron microscopy, were performed on cells as well as hippocampal tissues. The interactions between PKM2 and NRF2 proteins were detected using a coimmunoprecipitation (Co-IP) assay. Moreover, chromatin immunoprecipitation (ChIP), a luciferase reporter assay, and an electrophoretic mobility shift assay (EMSA) were performed to explore the mechanism by which PKM2 regulates the NRF2/GPX4 signaling pathway. The spatial memory of mice was evaluated using the Morris Water Maze test. Hematoxylin-eosin and Nissl staining were performed for histological examination. The results revealed that melatonin protected HT-22 neuronal cells from radiation-induced ferroptosis, as inferred from increased cell viability, decreased ROS production, reduced number of apoptotic cells, and less cristae, higher electron density in mitochondria. In addition, melatonin induced PKM2 nuclear transference, while PKM2 inhibition reversed the effects of melatonin. Further experiments demonstrated that PKM2 bound to and induced the nuclear translocation of NRF2, which regulated GPX4 transcription. Ferroptosis enhanced by PKM2 inhibition was also converted by NRF2 overexpression. In vivo experiments indicated that melatonin alleviated radiation-induced neurological dysfunction and injury in mice. In conclusion, melatonin suppressed ferroptosis to decrease radiation-induced hippocampal neuronal injury by activating the PKM2/NRF2/GPX4 signaling pathway.

Exploring boron applications in modern agriculture: Antifungal activities and mechanisms of phenylboronic acid derivatives.

BACKGROUND: The unreasonable use of chemical fungicides causes common adverse consequences that not only affect the environment, but also cause resistance and resurgence problems of plant pathogens, which are extremely harmful to human health, the economy, and the environment. Based on the rich biological activities of boron-based compounds, 82 phenylboronic acid derivatives were selected and their antifungal activities against six agricultural plant pathogens were determined. Combined with transcriptomics tools, the mechanism of action of compound A49 (2-chloro-5-trifluoromethoxybenzeneboronic acid) against Botrytis cinerea Pers (B. cinerea) was studied. RESULTS: The EC50 values of compounds A24, A25, A30, A31, A36, A41, A49 and B23 against all six fungi were under 10 µg/mL. Compound A49 displayed significant activity against B. cinerea (EC50 = 0.39 µg/mL), which was better than that of commercial fungicide boscalid (EC50 = 0.55 µg/mL). A49 not only inhibited the germination of B. cinerea spores, but also caused abnormal cell morphology, loss of cell membrane integrity, enhanced cell membrane permeability, and accumulation of intracellular reactive oxygen species. Further findings showed that A49 reduced cellular antioxidant activity, and peroxidase and catalase activities. Transcriptomic results indicated that A49 could degrade intracellular redox processes and alter the metabolism of some amino acids. Meanwhile, A49 showed obvious activity in vivo and low cytotoxicity to mammal cells. CONCLUSION: The boron-containing small molecule compounds had high efficiency and broad-spectrum antifungal activities against six plant pathogens, and are expected to be candidate compounds for a new class of antifungal drugs. © 2023 Society of Chemical Industry.

Risk Factors for Refractory Immune Checkpoint Inhibitor-related Pneumonitis in Patients With Lung Cancer.

Checkpoint inhibitor-related pneumonitis (CIP) is one of the most important immune checkpoint inhibitors side effects, and it is rare but fatal. Identifying patients at risk of refractory CIP before the start of CIP therapy is important for controlling CIP. We retrospectively analyzed the clinical data of 60 patients with lung cancer who developed CIP. Refractory CIP was defined as CIP with poor response to corticosteroid treatment, including CIP not relieved with corticosteroid administration or CIP recurrence during the corticosteroid tapering period. We analyzed clinical characteristics, peripheral blood biomarkers, treatment, and outcomes in nonrefractory and refractory CIP. Risk factors associated with refractory CIP were assessed. Among 60 patients with CIP, 16 (26.7%) had refractory CIP. The median onset time for patients with nonrefractory and those with refractory CIP was 16.57 (interquartile range [IQR], 6.82-28.14) weeks and 7.43 (IQR, 2.71-19.1) weeks, respectively. The level of lactate dehydrogenase (LDH) was significantly higher in the refractory CIP group at baseline (255 [222, 418] vs. 216 [183, 252], P =0.031) and at CIP onset (321.5 [216.75, 487.5] vs. 219 [198. 241], P =0.019). An LDH level >320 U/L at CIP onset was an independent risk factor of refractory CIP (odds ratio [OR], 8.889; 95% confidence interval [CI]: 1.294-61.058; P =0.026). The incidence of refractory CIP is high among patients with CIP. An increased LDH level at CIP onset is independently associated with refractory CIP. Monitoring LDH levels during immune checkpoint inhibitors treatment is recommended.

Deep learning predicts immune checkpoint inhibitor-related pneumonitis from pretreatment computed tomography images.

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of lung cancer, including both non-small cell lung cancer and small cell lung cancer. Despite the promising results of immunotherapies, ICI-related pneumonitis (ICIP) is a potentially fatal adverse event. Therefore, early detection of patients at risk for developing ICIP before the initiation of immunotherapy is critical for alleviating future complications with early interventions and improving treatment outcomes. In this study, we present the first reported work that explores the potential of deep learning to predict patients who are at risk for developing ICIP. To this end, we collected the pretreatment baseline CT images and clinical information of 24 patients who developed ICIP after immunotherapy and 24 control patients who did not. A multimodal deep learning model was constructed based on 3D CT images and clinical data. To enhance performance, we employed two-stage transfer learning by pre-training the model sequentially on a large natural image dataset and a large CT image dataset, as well as transfer learning. Extensive experiments were conducted to verify the effectiveness of the key components used in our method. Using five-fold cross-validation, our method accurately distinguished ICIP patients from non-ICIP patients, with area under the receiver operating characteristic curve of 0.918 and accuracy of 0.920. This study demonstrates the promising potential of deep learning to identify patients at risk for developing ICIP. The proposed deep learning model enables efficient risk stratification, close monitoring, and prompt management of ICIP, ultimately leading to better treatment outcomes.

Comprehensive Analysis of Expression and Prognostic Value of MS4As in Glioma.

Glioma is the most common malignancy of the nervous system with high mortality rates. The MS4A family members have been reported as potential prognostic biomarkers in several cancers; however, the relationship between the MS4A family and glioma has not been clearly confirmed. In our study, we explored the prognostic value of MS4As as well as their potential pro-cancer mechanisms of glioma. Using bioinformatics analysis methods based on the data from public databases, we found that the expression of MS4A4A, MS4A4E, MS4A6A, MS4A7, TMEM176A, and TMEM176B was significantly overexpressed in glioma tissues compared with that of normal tissues. The Kaplan-Meier method and Cox proportional hazards models revealed that high levels of MS4As can be associated with a poorer prognosis; TMEM176A, TMEM176B, age, WHO grade, and IDH status were identified as independent prognostic factors. Enrichment analysis predicted that MS4As were related to tumor-related pathways and immune response, which might regulate the process of MS4As promoting tumorigenesis. Additionally, we analyzed the correlations of MS4A expression with immune cells and immune inhibitory molecules. Finally, data from the cell culture suggested that knockdown of the TMEM176B gene contributes to the decreased proliferation and migration of glioma cells. In conclusion, MS4A4A, MS4A4E, MS4A6A, MS4A7, TMEM176A, and TMEM176B may act as potential diagnostic or prognostic biomarkers in glioma and play a role in forming the immune microenvironment in gliomas.

Mathematical Modeling Reveals That Sucrose Regulates Leaf Senescence via Dynamic Sugar Signaling Pathways.

Sucrose (Suc) accumulation is one of the key indicators of leaf senescence onset, but little is known about its regulatory role. Here, we found that application of high (120-150 mM) and low levels (60 mM) of Suc to young leaf (YL) and fully expanded leaf (FEL) discs, respectively, decreased chlorophyll content and maximum photosynthetic efficiency. Electrolyte leakage and malondialdehyde levels increased at high Suc concentrations (90-120 mM in YL and 60 and 150 mM in FEL discs). In FEL discs, the senescence-associated gene NtSAG12 showed a gradual increase in expression with increased Suc application; in contrast, in YL discs, NtSAG12 was upregulated with low Suc treatment (60 mM) but downregulated at higher levels of Suc. In YL discs, trehalose-6-phosphate (T6P) accumulated at a low half-maximal effective concentration (EC50) of Suc (1.765 mM). However, T6P levels declined as trehalose 6 phosphate synthase (TPS) content decreased, resulting in the maximum velocity of sucrose non-fermenting-1-related protein kinase (SnRK) and hexokinase (HXK) occurring at higher level of Suc. We therefore speculated that senescence was induced by hexose accumulation. In FEL discs, the EC50 of T6P occurred at a low concentration of Suc (0.9488 mM); T6P levels progressively increased with higher TPS content, which inhibited SnRK activity with a dissociation constant (Kd) of 0.001475 U/g. This confirmed that the T6P-SnRK complex induced senescence in detached FEL discs.

Investigation of sugar signaling behaviors involved in sucrose-induced senescence initiation and progression in N. tabacum.

Sugar is involved in initiating leaf senescence. However, its regulatory role, especially as a signal in the senescence process, is unclear. Therefore, this study was designed to illustrate how sugar stimulates the onset of leaf senescence and controls sugar homeostasis through the T6P-SnRK (sucrose non-fermenting (SNF)-related kinase) and HXK (hexokinase) signaling pathways. We used a leaf disc system detached from fully expanded leaves of Nicotiana tabacum cv. K326 and designed a time-course study (days 3, 5, 7, and 9) with exogenously gradient concentrations (0, 30, 60, 90, 120, and 150 mM) of sucrose (Suc) treatment to identify how Suc application affects sugar metabolism and induces senescence. Our results revealed that early decreases of Fv/Fm and increases in electrolyte leakage responded to Suc on day 3. Furthermore, a substantial increase in lipid peroxidation and up-regulated expression of senescence marker genes (NtSAG12) (except 60 mM on day 3) responded sequentially by day 5. The glucose, G6P, and HXK contents were first induced by Suc on day 3 and then repressed from day 5 to day 7. However, exogenous Suc treatment significantly improved the TPS content and the subsequent precursor T6P from day 3 to day 7. Following exogenous Suc treatments, the transcript level of NtSnRK1 was markedly down-regulated from day 3 to day 7. On the other hand, a linear regression analysis demonstrated that the T6P-NtSnRK1 signaling pathway was strongly associated with senescence initiation, and was accompanied by membrane degradation and NtCP1/NtSAG12 up-regulation by day 3. The T6P-NtSnRK1 signaling pathway experienced membrane and chloroplast degradation by day 5. HXK functioned as a metabolic enzyme promoting Glc-G6P and as a Glc sensor, accelerating the initiation of senescence through the HXK-dependent pathway by repressing PSII by day 3 and the senescence process through the Glycolytic pathway by day 7. These physiological, biochemical, and molecular analyses demonstrate that exogenous Suc regulates T6P accumulation, inducing senescence through the NtSnRK signaling pathway. These results illustrate the role of Suc and the transition of the sugar signaling pathway during the progression of senescence initiation.

To Summarize and Analyze the Epidemiological Characteristics and Prognostic Risk Factors of Patients with Pelvic Fracture Complicated with Perineal Injury.

This study is aimed at summarizing and analyzing the epidemiological characteristics and prognostic risk factors of patients with a pelvic fracture with perineal injury. The clinical data of 153 patients with pelvic fracture with perineal injury treated in our hospital from January 2012 to June 2021 were analyzed retrospectively. The data of sex, age, injury mechanism, pelvic fracture type, shock index (SI), perineal wound depth, concomitant injury, total hospital stay, and death were collected by the electronic medical record system. Among the 153 patients, there were 94 males and 59 females, with an average age of (43.2 ± 16.8) years. The cases were mainly concentrated into two age groups: 20-29 years old and 50-59 years old. In a year, pelvic fractures were mainly concentrated in 1-2 months and 11-12 months. In terms of injury time, there were mainly two periods of time in a day: 10 : 00～12 : 00 and 15 : 00～18 : 00. The MOTS-RTS scores of the patients in the undead group and the dead group were (7.12 ± 1.52), (2.69 ± 0.96), ISS scores were (27.36 ± 15.84), (61.32 ± 7.08), GCS scores were (12.84 ± 3.69), (4.13 ± 1.25), APACH II scores were (12.87 ± 8.84), (32.41 ± 6.98), and SOFA scores were (6.68 ± 5.87), (17.12 ± 3.12). The MOTS-RTS and GCS scores of the nondeath group were significantly higher, while the ISS score, APACH II score, SOFA score, and shock index were significantly lower. The overall mortality rate of 153 patients was 13.7%. The average area of perineal trauma in undead and dead patients was (54.5 ± 113.52) cm2 and (262.63 ± 300.84) cm2, respectively. The average depth of perineal trauma was (9.63 ± 7.22) cm and (16.23 ± 10.13) cm, respectively. The larger the area of perineal injury and the deeper the depth of perineal trauma, the worse their prognosis. Cox multivariate analysis showed that complications, MOTS-RTS score, ISS score, GCS score, perineal trauma area, and perineal trauma depth were independent risk factors affecting the prognosis of patients with pelvic fracture with perineal injury. Most of the patients with pelvic fracture complicated with perineal injury are 20-29 years old and 50-59 years old. The more serious the perineal injury is, the higher the mortality is. The main causes of death are refractory hemorrhagic shock and infection.

Design, Synthesis, and Antimicrobial Activity of Quindoline Derivatives Inspired by the Cryptolepine Alkaloid.

Based on the structural characteristics of the cryptolepine alkaloid, a series of new quindoline derivatives bearing various substituents were prepared and evaluated for their fungicidal and antibacterial activities. Bioassay results showed that compound D7 displayed superior in vitro fungicidal activities against Sclerotinia sclerotiorum, Botrytis cinerea, Fusarium graminearum, and Rhizoctonia solani with EC50 values of 0.780, 3.62, 1.59, and 2.85 µg/mL, respectively. Compound A7 showed apparent antibacterial activities toward Xanthomonas oryzae pv. oryzae with a minimum inhibitory concentration (MIC) value of 3.12 µg/mL. Significantly, in vivo antifungal activity suggested that the curative effect (98.3%) of compound D7 was comparable to that of the positive control azoxystrobin (96.7%) at 100 µg/mL. Preliminary mechanistic studies showed that compound D7 might cause mycelial abnormality of S. sclerotiorum, cell membrane breakage, accumulation of reactive oxygen species (ROS), and inhibition of sclerotia formation. Therefore, compound D7 could be a novel broad-spectrum fungicidal candidate against plant fungal diseases.

microRNA-10a-5p from gastric cancer cell-derived exosomes enhances viability and migration of human umbilical vein endothelial cells by targeting zinc finger MYND-type containing 11.

Tumor-derived exosomes (exo) could modulate the biological behaviors of human umbilical vein endothelial cells (HUVECs). Here, the role of microRNA (miR)-10a-5p-modified gastric cancer (GC) cells-derived exo for HUVECs was studied. GC tissue specimens were collected, and miR-10a-5p and zinc finger MYND-type containing 11 (ZMYND11) levels were determined. HUVECs interfered with ZMYND11 or miR-10a-5p-related oligonucleotides. Exo was extracted from GC cells (HGC-27 exo), and miR-10a-5p mimic-modified HGC-27 exo were co-cultured with HUVECs. HUVECs viability, migration and angiogenesis were evaluated, and miR-10a-5p/ZMYND11 crosstalk was explored. It was observed that GC patients had raised miR-10a-5p and reduced ZMYND11, and miR-10a-5p negatively mediated ZMYND11 expression. Suppression of miR-10a-5p or overexpression of ZMYND11 inhibited viability, migration and tube formation ability of HUVECs. Notably, miR-10a-5p mimic-modified HGC-27 exo enhanced the viability, migration and tube formation ability of HUVECs, but this effect was impaired after up-regulating ZMYND11. In summary, miR-10a-5p from GC cells-derived exo enhances viability and migration of HUVECs by suppressing ZMYND11.

GDF15 expression in glioma is associated with malignant progression, immune microenvironment, and serves as a prognostic factor.

AIMS: Growth differentiation factor 15 (GDF15) is involved in lots of crucial inflammatory and immune response. The clinical and immune features for GDF15 in glioma have not been specifically investigated so far. METHODS: Gene expression profiles obtained from public glioma datasets were used to explore the biological function of GDF15 and its impact on immune microenvironment. Interference with GDF15 in several glioma cell lines to verify its functions in vitro. Survival data were used for the survival analysis and establishment of a nomogram predictive model. RESULTS: GDF15 was up-regulated in various malignant phenotypes of glioma. Function analysis and in vitro experiments revealed that GDF15 was associated with malignant progression and NF-κB pathway. GDF15 was closely correlated to inflammatory response, infiltrating immune cells, and immune checkpoint molecules, especially in lower grade glioma (LGG). High expression level of GDF15 predicted poor survival in LGG, while the effect on glioblastoma (GBM) was not significant. A nomogram predictive model combining GDF15 and other prognostic factors was constructed and showed ideal predictive performance. CONCLUSIONS: GDF15 could serve as an interesting prognostic biomarker for LGG. Regulating the expression of GDF15 may help solve the dilemma of immunotherapy in glioma.

Design, synthesis and biological evaluation of novel evodiamine and rutaecarpine derivatives against phytopathogenic fungi.

Evodiamine and rutaecarpine are two alkaloids isolated from traditional Chinese herbal medicine Evodia rutaecarpa, which have been reported to have various biological activities in past decades. To explore the potential applications for evodiamine and rutaecarpine alkaloids and their derivatives, various kinds of evodiamine and rutaecarpine derivatives were designed and synthesized. Their antifungal profile against six phytopathogenic fungi Rhizoctonia solani, Botrytis cinerea, Fusarium graminearum, Fusarium oxysporum, Sclerotinia sclerotiorum, and Magnaporthe oryzae were evaluated for the first time. Furthermore, a series of modified imidazole derivatives of rutaecarpine were synthesized to investigate the structure-activity relationship. The results of antifungal activities in vitro showed that imidazole derivative of rutaecarpine A1 exhibited broad-spectrum inhibitory activities against R. solani, B. cinerea, F. oxysporum, S. sclerotiorum, M. oryzae and F. graminearum with EC50 values of 1.97, 5.97, 12.72, 2.87 and 16.58 µg/mL, respectively. Preliminary mechanistic studies showed that compound A1 might cause mycelial abnormalities of S. sclerotiorum, mitochondrial distortion and swelling, and inhibition of sclerotia formation and germination. Moreover, the curative effects of compound A1 were 94.7%, 81.5%, 80.8%, 65.0% at 400, 200, 100, 50 µg/mL in vivo experiments, which was far more effective than the positive control azoxystrobin. Significantly, no phytotoxicity of compound A1 on oilseed rape leaves was observed obviously even at a high concentration of 400 µg/mL. Therefore, compound A1 is expected to be a novel leading structure for the development of new antifungal agents.

Arabidopsis cryptochrome 1 undergoes COP1 and LRBs-dependent degradation in response to high blue light.

Arabidopsis cryptochrome 1 (CRY1) is an important blue light photoreceptor that promotes photomorphogenesis under blue light. The blue light photoreceptors CRY2 and phototropin 1, and the red/far-red light photoreceptors phytochromes B and A undergo degradation in response to blue and red light, respectively. This study investigated whether and how CRY1 might undergo degradation in response to high-intensity blue light (HBL). We demonstrated that CRY1 is ubiquitinated and degraded through the 26S proteasome pathway in response to HBL. We found that the E3 ubiquitin ligase constitutive photomorphogenic 1 (COP1) is involved in mediating HBL-induced ubiquitination and degradation of CRY1. We also found that the E3 ubiquitin ligases LRBs physically interact with CRY1 and are also involved in mediating CRY1 ubiquitination and degradation in response to HBL. We further demonstrated that blue-light inhibitor of cryptochromes 1 interacts with CRY1 in a blue-light-dependent manner to inhibit CRY1 dimerization/oligomerization, leading to the repression of HBL-induced degradation of CRY1. Our findings indicate that the regulation of CRY1 stability in HBL is coordinated by COP1 and LRBs, which provides a mechanism by which CRY1 attenuates its own signaling and optimizes photomorphogenesis under HBL.

Design, Synthesis, and Antifungal Evaluation of Luotonin A Derivatives against Phytopathogenic Fungi.

Crop diseases caused by fungi threaten food security and exacerbate the food crisis. Inspired by the application of fungicide candidates from natural products in agrochemical discovery, a series of luotonin A derivatives were designed, synthesized, and evaluated for their antifungal activities against five plant fungi. Most of these compounds exhibited significant fungicidal activity against Botrytis cinerea in vitro with EC50 values less than 1 µg/mL. Among them, compounds w7, w8, w12, and w15 showed superior antifungal activity against B. cinerea with EC50 values of 0.036, 0.050, 0.042, and 0.048 µg/mL, respectively, which were more potent than boscalid (EC50 = 1.790 µg/mL). Preliminary mechanism studies revealed that compound w7 might pursue its antifungal activity by disrupting the fungal cell membrane and cell wall. Moreover, in vivo bioassay also indicated that compound w7 could be effective for the control of B. cinerea. The above results evidenced the potential of luotonin A derivatives as novel and promising candidate fungicides.

The Antifungal Mechanism of Isoxanthohumol from Humulus lupulus Linn.

Humulus lupulus Linn. is a traditional medicinal and edible plant with several biological properties. The aims of this work were: (1) to evaluate the in vitro antifungal activity of H. lupulus ethanolic extract; (2) to study the in vitro and in vivo antifungal activity of isoxanthohumol, an isoprene flavonoid from H. lupulus, against Botrytis cinerea; and (3) to explore the antifungal mechanism of isoxanthohumol on B. cinerea. The present data revealed that the ethanolic extract of H. lupulus exhibited moderate antifungal activity against the five tested phytopathogenic fungi in vitro, and isoxanthohumol showed highly significant antifungal activity against B. cinerea, with an EC50 value of 4.32 µg/mL. Meanwhile, it exhibited moderate to excellent protective and curative efficacies in vivo. The results of morphologic observation, RNA-seq, and physiological indicators revealed that the antifungal mechanism of isoxanthohumol is mainly related to metabolism; it affected the carbohydrate metabolic process, destroyed the tricarboxylic acid (TCA) cycle, and hindered the generation of ATP by inhibiting respiration. Further studies indicated that isoxanthohumol caused membrane lipid peroxidation, thus accelerating the death of B. cinerea. This study demonstrates that isoxanthohumol can be used as a potential botanical fungicide for the management of phytopathogenic fungi.

Antifungal Activity and Action Mechanism Study of Coumarins from Cnidium monnieri Fruit and Structurally Related Compounds.

The increasing resistance of plant diseases caused by phytopathogenic fungi highlights the need for highly effective and environmentally benign agents. The antifungal activities of Cnidium monnieri fruit extracts and five isolated compounds as well as structurally related coumarins against five plant pathogenic fungi were evaluated. The acetone extract, which contained the highest amount of five coumarins, showed strongest antifungal activity. Among the coumarin compounds, we found that 4-methoxycoumarin exhibited stronger and broader antifungal activity against five phytopathogenic fungi, and was more potent than osthol. Especially, it could significantly inhibit the growth of Rhizoctonia solani mycelium with an EC50 value of 21 µg mL-1 . Further studies showed that 4-methoxycoumarin affected the structure and function of peroxisomes, inhibited the ß-oxidation of fatty acids, decreased the production of ATP and acetyl coenzyme A, and then accumulated ROS by damaging MMP and the mitochondrial function to cause the cell death of R. solani mycelia. 4-Methoxycoumarin presented antifungal efficacy in a concentration- dependent manner in vivo and could be used to prevent the potato black scurf. This study laid the foundation for the future development of 4-methoxycournamin as an alternative and friendly biofungicide.