The orphan receptor Nur77 binds cytoplasmic LPS to activate the non-canonical NLRP3 inflammasome.

Intracellular sensing of lipopolysaccharide (LPS) by murine caspase-11 or human caspase-4 initiates a protease cascade, termed the non-canonical inflammasome, that results in gasdermin D (GSDMD) processing and subsequent NLRP3 inflammasome activation. In an effort aimed at identifying additional sensors for intracellular LPS by biochemical screening, we identified the nuclear orphan receptor Nur77 as an LPS-binding protein in macrophage lysates. Nr4a1-/- macrophages exhibited impaired activation of the NLRP3 inflammasome, but not caspase-11, in response to LPS. Biochemical mapping revealed that Nur77 bound LPS directly through a domain in its C terminus. Yeast two-hybrid assays identified NLRP3 as a binding partner for Nur77. The association between Nur77 and NLRP3 required the presence of LPS and dsDNA. The source of dsDNA was the mitochondria, requiring the formation of gasdermin-D pores. In vivo, Nur77 deficiency ameliorated host response to endotoxins. Thus, Nur77 functions as an intracellular LPS sensor, binding mitochondrial DNA and LPS to activate the non-canonical NLRP3 inflammasome.

Lactate administration improves laboratory parameters in murine models of iron overload.

ABSTRACT: Current iron overload therapeutics have inherent drawbacks including perpetuated low hepcidin. Here, we unveiled that lactate, a potent hepcidin agonist, effectively reduced serum and hepatic iron levels in mouse models of iron overload with an improved erythropoiesis in ß-thalassemic mice.

SARS-CoV-2 nucleocapsid suppresses host pyroptosis by blocking Gasdermin D cleavage.

SARS-CoV-2 is an emerging coronavirus that causes dysfunctions in multiple human cells and tissues. Studies have looked at the entry of SARS-CoV-2 into host cells mediated by the viral spike protein and human receptor ACE2. However, less is known about the cellular immune responses triggered by SARS-CoV-2 viral proteins. Here, we show that the nucleocapsid of SARS-CoV-2 inhibits host pyroptosis by blocking Gasdermin D (GSDMD) cleavage. SARS-CoV-2-infected monocytes show enhanced cellular interleukin-1ß (IL-1ß) expression, but reduced IL-1ß secretion. While SARS-CoV-2 infection promotes activation of the NLRP3 inflammasome and caspase-1, GSDMD cleavage and pyroptosis are inhibited in infected human monocytes. SARS-CoV-2 nucleocapsid protein associates with GSDMD in cells and inhibits GSDMD cleavage in vitro and in vivo. The nucleocapsid binds the GSDMD linker region and hinders GSDMD processing by caspase-1. These insights into how SARS-CoV-2 antagonizes cellular inflammatory responses may open new avenues for treating COVID-19 in the future.

Interfacial Polarization Locked Flexible ß-Phase Glycine/Nb2 CTx Piezoelectric Nanofibers.

Biomolecular piezoelectric materials show great potential in the field of wearable and implantable biomedical devices. Here, a self-assemble approach is developed to fabricating flexible ß-glycine piezoelectric nanofibers with interfacial polarization locked aligned crystal domains induced by Nb2 CTx nanosheets. Acted as an effective nucleating agent, Nb2 CTx nanosheets can induce glycine to crystallize from edges toward flat surfaces on its 2D crystal plane and form a distinctive eutectic structure within the nanoconfined space. The interfacial polarization locking formed between O atom on glycine and Nb atom on Nb2 CTx is essential to align the ß-glycine crystal domains with (001) crystal plane intensity extremely improved. This ß-phase glycine/Nb2 CTx nanofibers (Gly-Nb2 C-NFs) exhibit fabulous mechanical flexibility with Young's modulus of 10 MPa, and an enhanced piezoelectric coefficient of 5.0 pC N-1 or piezoelectric voltage coefficient of 129 × 10-3 Vm N-1 . The interface polarization locking greatly improves the thermostability of ß-glycine before melting (≈210°C). A piezoelectric sensor based on this Gly-Nb2 C-NFs is used for micro-vibration sensing in vivo in mice and exhibits excellent sensing ability. This strategy provides an effective approach for the regular crystallization modulation for glycine crystals, opening a new avenue toward the design of piezoelectric biomolecular materials induced by 2D materials.

Understanding immune microenvironment alterations in the brain to improve the diagnosis and treatment of diverse brain diseases.

Abnormal inflammatory states in the brain are associated with a variety of brain diseases. The dynamic changes in the number and function of immune cells in cerebrospinal fluid (CSF) are advantageous for the early prediction and diagnosis of immune diseases affecting the brain. The aggregated factors and cells in inflamed CSF may represent candidate targets for therapy. The physiological barriers in the brain, such as the blood‒brain barrier (BBB), establish a stable environment for the distribution of resident immune cells. However, the underlying mechanism by which peripheral immune cells migrate into the brain and their role in maintaining immune homeostasis in CSF are still unclear. To advance our understanding of the causal link between brain diseases and immune cell status, we investigated the characteristics of immune cell changes in CSF and the molecular mechanisms involved in common brain diseases. Furthermore, we summarized the diagnostic and treatment methods for brain diseases in which immune cells and related cytokines in CSF are used as targets. Further investigations of the new immune cell subtypes and their contributions to the development of brain diseases are needed to improve diagnostic specificity and therapy.

Using multi-omics to explore the effect of Bacillus velezensis SAAS-63 on resisting nutrient stress in lettuce.

To avoid the unreasonable use of chemical fertilizer, an environmentally friendly means of improving soil fertility is required. This study explored the role of the plant growth-promoting rhizosphere bacteria (PGPR) strain Bacillus velezensis SAAS-63 in improving nutrient stress in lettuce. Compared with no inoculation, B. velezensis SAAS-63 inoculants exhibited significantly increased fresh weight, root length, and shoot height under nutrient deficiency, as well as improved antioxidant activities and proline contents. The exogenous addition of B. velezensis SAAS-63 also significantly increased the accumulation of macroelements and micronutrients in lettuce. To elucidate the resistance mechanisms induced by B. velezensis SAAS-63 under nutrient stress, high-throughput sequencing and multi-omics analysis were performed. Inoculation with B. velezensis SAAS-63 altered the microbial community of the rhizosphere and increased the relative abundances of Streptomyces, Actinoallomurus, Verrucomicrobia, and Chloroflexi. It is worth noting that the inoculant SAAS-63 can affect plant rhizosphere metabolism. The inoculant changed the metabolic flow of phenylpropanoid metabolic pathway under nutrient deficiency and promoted phenylalanine to participate more in the synthesis of lignin precursors and coumarin substances by inhibiting the synthesis of flavone and isoflavone, thus improving plant resistance. This study showed that the addition of inoculant SAAS-63 could help plants recruit microorganisms to decompose and utilize trehalose and re-established the carbon metabolism of the plant rhizosphere. Additionally, microbes were found to be closely related to the accumulation of metabolites based on correlation analysis. The results indicated that the addition of PGPRs has an important role in regulating soil rhizosphere microbes and metabolism, providing valuable information for understanding how PGPRs affect complex biological processes and enhance plant adaptation to nutrient deficiency. KEY POINTS: • Inoculation with SAAS-63 significantly promoted plant growth under nutrient-deficient conditions • Inoculation with SAAS-63 affected rhizosphere microbial diversity and community structure • Inoculation with SAAS-63 affected plant rhizosphere metabolism and induced plants to synthesize substances that resist stress.

Multiple Perspectives of Study on the Potential of Bacillus amyloliquefaciens JB20221020 for Alleviating Nutrient Stress in Lettuce.

Soil nutrient deficiency has become a key factor limiting crop growth. Plant growth-promoting rhizobacteria (PGPR) are vital in resisting abiotic stress. In this study, we investigated the effects of inoculation with Bacillus amyloliquefaciens JB20221020 on the physiology, biochemistry, rhizosphere microorganisms, and metabolism of lettuce under nutrient stress. Pot experiments showed that inoculation with B. amyloliquefaciens JB20221020 significantly promoted lettuce growth under nutrient deficiency. At the same time, the activities of the antioxidant enzymes superoxide dismutase, peroxidase, and catalase and the content of proline increased, and the content of Malondialdehyde decreased in the lettuce inoculated with B. amyloliquefaciens JB20221020. Inoculation with B. amyloliquefaciens JB20221020 altered the microbial community of the rhizosphere and increased the relative abundances of Myxococcales, Deltaproteobacteria, Proteobacteria, Devosia, and Verrucomicrobia. Inoculation also altered the rhizosphere metabolism under nutrient deficiency. The folate metabolism pathway was significantly enriched in the Kyoto Encyclopedia of Genes and Genomes enrichment analysis. This study explored the interaction between plants and microorganisms under nutrient deficiency, further explained the critical role of rhizosphere microorganisms in the process of plant nutrient stress, and provided a theoretical basis for the use of microorganisms to improve plant resistance.

Development and validation of a predictive model for PACU hypotension in elderly patients undergoing sedated gastrointestinal endoscopy.

BACKGROUND: Hypotension, characterized by abnormally low blood pressure, is a frequently observed adverse event in sedated gastrointestinal endoscopy procedures. Although the examination time is typically short, hypotension during and after gastroscopy procedures is frequently overlooked or remains undetected. This study aimed to construct a risk nomogram for post-anesthesia care unit (PACU) hypotension in elderly patients undergoing sedated gastrointestinal endoscopy. METHODS: This study involved 2919 elderly patients who underwent sedated gastrointestinal endoscopy. A preoperative questionnaire was used to collect data on patient characteristics; intraoperative medication use and adverse events were also recorded. The primary objective of the study was to evaluate the risk of PACU hypotension in these patients. To achieve this, the least absolute shrinkage and selection operator (LASSO) regression analysis method was used to optimize variable selection, involving cyclic coordinate descent with tenfold cross-validation. Subsequently, multivariable logistic regression analysis was applied to build a predictive model using the selected predictors from the LASSO regression. A nomogram was visually developed based on these variables. To validate the model, a calibration plot, receiver operating characteristic (ROC) curve, and decision curve analysis (DCA) were used. Additionally, external validation was conducted to further assess the model's performance. RESULTS: The LASSO regression analysis identified predictors associated with an increased risk of adverse events during surgery: age, duration of preoperative water abstinence, intraoperative mean arterial pressure (MAP) <65 mmHg, decreased systolic blood pressure (SBP), and use of norepinephrine (NE). The constructed model based on these predictors demonstrated moderate predictive ability, with an area under the ROC curve of 0.710 in the training set and 0.778 in the validation set. The DCA indicated that the nomogram had clinical applicability when the risk threshold ranged between 20 and 82%, which was subsequently confirmed in the external validation with a range of 18-92%. CONCLUSION: Incorporating factors such as age, duration of preoperative water abstinence, intraoperative MAP <65 mmHg, decreased SBP, and use of NE in the risk nomogram increased its usefulness for predicting PACU hypotension risk in elderly patient undergoing sedated gastrointestinal endoscopy.

Newly identified lncRNA-45 promotes breast cancer metastasis through activating the mTOR signaling pathway.

BACKGROUND: Metastasis, a complex multi-stage process, is the primary cause of breast cancer-related death. Unfortunately, the molecular mechanisms underlying tumor metastasis have not been fully elucidated thus far. Long noncoding RNAs (lncRNAs) dictate the behaviours of tumor cells via multiple signaling pathways, resulting in tumor cell migration and invasion, as well as all stages of cancer progression. LncRNAs function as regulators in shaping cellular activities directly through influencing key genes involved in biological processes of the tumor, and representing promising novel targets in cancer diagnosis and therapy. We therefore sought to define the correlations between lncRNA expression and breast cancer metastasis, especially to investigate the functional pathway underlying lncRNA-mediated tumor invasion and metastasis process. RESULTS: In this study, we compared the lncRNA transcriptome profiles between primary breast cancer 4T1 cells and high metastatic 4T1-LG12 cells. We found that many differently expressed lncRNAs greatly correlated to the metastatic propensity of 4T1-LG12 cells, particularly lncRNA-45, a new lncRNA without functional annotations, which was found to be the most upregulated lncRNA transcribed by an internal region within the regulatory associated with protein of mechanistic target of rapamycin kinase (mTOR) complex 1 (Rptor) gene. LncRNA-45 was uncovered to be involved in the epithelial-to-mesenchymal transition process of breast cancer cells, as evidenced by the observation that lncRNA-45 knockdown significantly suppressed the invasive capability of parental 4T1-LG12 cells. Molecular mechanistic investigation showed that reduced activity of mTORC1-associated pathway led to a decrease of total ribosomal protein S6 kinase, polypeptide 1 (S6K1) content and enhancement of autophagy, consequently compromising the metastatic propensity in lncRNA-45 knockdown cells. CONCLUSIONS: Overall, our experiments uncovered that the newly identified lncRNA-45 played a regulatory role in breast cancer cell metastasis.

Single-cell RNA sequencing profiles reveal cell type-specific transcriptional regulation networks conditioning fungal invasion in maize roots.

Stalk rot caused by Fusarium verticillioides (Fv) is one of the most destructive diseases in maize production. The defence response of root system to Fv invasion is important for plant growth and development. Dissection of root cell type-specific response to Fv infection and its underlying transcription regulatory networks will aid in understanding the defence mechanism of maize roots to Fv invasion. Here, we reported the transcriptomes of 29 217 single cells derived from root tips of two maize inbred lines inoculated with Fv and mock condition, and identified seven major cell types with 21 transcriptionally distinct cell clusters. Through the weighted gene co-expression network analysis, we identified 12 Fv-responsive regulatory modules from 4049 differentially expressed genes (DEGs) that were activated or repressed by Fv infection in these seven cell types. Using a machining-learning approach, we constructed six cell type-specific immune regulatory networks by integrating Fv-induced DEGs from the cell type-specific transcriptomes, 16 known maize disease-resistant genes, five experimentally validated genes (ZmWOX5b, ZmPIN1a, ZmPAL6, ZmCCoAOMT2, and ZmCOMT), and 42 QTL or QTN predicted genes that are associated with Fv resistance. Taken together, this study provides not only a global view of maize cell fate determination during root development but also insights into the immune regulatory networks in major cell types of maize root tips at single-cell resolution, thus laying the foundation for dissecting molecular mechanisms underlying disease resistance in maize.

Bispecific anti-CD3×anti-CD155 antibody mediates T-cell immunotherapy in human haematologic malignancies.

T cells are important components in the cell-mediated antitumour response. In recent years, bispecific antibodies (Bi-Abs) have become promising treatments because of their ability to recruit T cells that kill tumours. Here, we demonstrate that CD155 is expressed in a wide range of human haematologic tumours and report on the ability of the bispecific antibody anti-CD3 x anti-CD155 (CD155Bi-Ab) to activate T cells targeting malignant haematologic cells. The specific cytolytic effect of T cells armed with CD155Bi-Ab was evaluated by quantitative luciferase assay, and the results showed that the cytolytic effect of these cells was accompanied by an increase in the level of the cell-killing mediator perforin. Moreover, compared with their unarmed T-cell counterparts, CD155Bi-Ab-armed T cells induced significant cytotoxicity in CD155-positive haematologic tumour cells, as indicated by lactate dehydrogenase assays, and these results were accompanied by increased granzyme B secretion. Furthermore, CD155Bi-Ab-armed T cells produced more T-cell-derived cytokines, including TNF-α, IFN-γ, and IL-2. In conclusion, CD155Bi-Ab enhances the ability of T cells to kill haematologic tumour cells, and therefore, CD155 may serve as a novel target for immunotherapy against haematologic malignancies.

Transitions of Collective Motions Driven by Phase Resetting.

The front cover artwork is provided by Prof. Gao's group. The image shows the motion patterns transition of the active gel group under the step light intensity, which describes the mechanism of a new collective emergence structure. Read the full text of the Research Article at 10.1002/cphc.202300054.

Transitions of Collective Motions Driven by Phase Resetting.

Abrupt (i. e. step) environmental changes, such as natural disasters or the intervention of predators, can alter the internal dynamics of groups with active units, leading to the rapid destruction and/or restructuring of the group, with the emergence of new collective structures that endow the system with adaptability. Few studies, to date, have considered the influence of abrupt environmental changes on emergent behavior. Here, we use a model of active matter, the Belousov-Zhabotinsky (BZ) self-oscillating gel, to study the mechanism of formation and transition between modes of collective locomotion caused by changes of illumination intensity in arrays of interacting photosensitive active units. New forms of collective motion can be generated by step changes of illumination intensity. These transformations arise from the phase resetting and wave-signal regeneration induced by the abrupt parameter variation, while gradual change results in different evolution of collective motion. Our results not only suggest a novel mechanism for emergence, but also imply that new collective behaviors could be accessible via discontinuous parameter changes.

Microplastics and Nanoplastics Impair the Biophysical Function of Pulmonary Surfactant by Forming Heteroaggregates at the Alveolar-Capillary Interface.

Microplastics (MPs) are ubiquitous environmental pollutants produced through the degradation of plastic products. Nanoplastics (NPs), commonly coexisting with MPs in the environment, are submicrometer debris incidentally produced from fragmentation of MPs. We studied the biophysical impacts of MPs/NPs derived from commonly used commercial plastic products on a natural pulmonary surfactant extracted from calf lung lavage. It was found that in comparison to MPs/NPs derived from lunch boxes made of polypropylene or from drinking water bottles made of poly(ethylene terephthalate), the MP/NP derived from foam packaging boxes made of polystyrene showed the highest adverse impact on the biophysical function of the pulmonary surfactant. Accordingly, intranasal exposure of MP/NP derived from the foam boxes also induced the most serious proinflammatory responses and lung injury in mice. Atomic force microscopy revealed that NP particles were adsorbed on the air-water surface and heteroaggregated with the pulmonary surfactant film. These results indicate that although the incidentally formed NPs only make up a small mass fraction, they likely play a predominant role in determining the nano-bio interactions and the lung toxicity of MPs/NPs by forming heteroaggregates at the alveolar-capillary interface. These findings may provide novel insights into understanding the health impact of MPs and NPs on the respiratory system.

PM2.5 Increases Systemic Inflammatory Cells and Associated Disease Risks by Inducing NRF2-Dependent Myeloid-Biased Hematopoiesis in Adult Male Mice.

Although PM2.5 (fine particles with aerodynamic diameter <2.5 µm) exposure shows the potential to impact normal hematopoiesis, the detailed alterations in systemic hematopoiesis and the underlying mechanisms remain unclear. For hematopoiesis under steady-state or stress conditions, nuclear factor erythroid 2-related factor 2 (NRF2) is essential for regulating hematopoietic processes to maintain blood homeostasis. Herein, we characterized changes in the populations of hematopoietic stem progenitor cells and committed hematopoietic progenitors in the lungs and bone marrow (BM) of wild-type and Nrf2-/- C57BL/6J male mice. PM2.5-induced NRF2-dependent biased hematopoiesis toward myeloid lineage in the lungs and BM generates excessive numbers of various inflammatory immune cells, including neutrophils, monocytes, and platelets. The increased population of these immune cells in the lungs, BM, and peripheral blood has been associated with observed pulmonary fibrosis and high disease risks in an NRF2-dependent manner. Therefore, although NRF2 is a protective factor against stressors, upon PM2.5 exposure, NRF2 is involved in stress myelopoiesis and enhanced PM2.5 toxicity in pulmonary injury, even leading to systemic inflammation.

Deep vein thrombosis in a patient with Cronkhite-Canada syndrome: a complex case report.

BACKGROUND: Cronkhite-Canada syndrome (CCS) is a rare disease characterized by generalized gastrointestinal polyps, ectodermal abnormalities and variable gastrointestinal symptoms. Few cases to date have described complications with deep vein thrombosis (DVT). Here we reported a rare case of CCS concomitant with DVT. The patient's clinical details, endoscopic findings, safety, and efficacy are reported. CASE PRESENTATION: A 58-year-old patient was admitted to our hospital with recurrent diarrhea, overall abnormal appearance, including hyperpigmentation, hair loss and onychodystrophy, and multiple polyps distributed along the gastrointestinal tract except the esophagus. After considerable assessment, the patient was diagnosed with CCS. She was also diagnosed with concurrent DVT, nephrotic syndrome, and infectious enteritis during the course of disease. After treatment with a combination of methylprednisolone, mesalazine, antibiotics, rivaroxaban, and nutritional support during the 24 months of following the patient in this case, the clinical manifestations and endoscopic findings reached complete remission two years after the diagnosis. CONCLUSION: To our knowledge, this study is the first case of CCS complicated with DVT reported in China. Although rare, it is important to consider that DVT may occur after CCS and that it is vital to conduct careful follow-up.

A retrospective cohort study of tamoxifen versus surgical treatment for ER-positive gynecomastia.

BACKGROUND: Gynecomastia is a common condition in clinical practice. The present study aimed to review the clinical data of ER-positive gynecomastia patients treated by tamoxifen (TAM) versus surgery and discussed the clinical effects of the two treatment strategies. METHOD: We retrospectively collected the clinical indicators of patients with unilateral or bilateral gynecomastia who received treatment at our hospital between April 2018 and December 2021. Depending on the treatment received, the patients were divided into TAM and surgery groups. RESULT: A total of 170 patients were recruited, including 91 patients in TAM group and 79 patients in surgery group. The age of the patients differed significantly between the TAM and surgery groups (P < 0.01). The estrogen level was closer in patients with stable and progressive disease, but significantly different in patients of glandular shrinkage in TAM group (P < 0.01). The proportion of patients achieving stable disease was higher among those with clinical grade 1-2. Among patients classified as clinical grade 3, the proportion of patients achieving glandular shrinkage of the breast was higher after TAM treatment (P < 0.05). The age and length of hospital stay were significantly different in patients undergoing open surgery than minimally invasive rotary cutting surgery and mammoscopic-assisted glandular resection (P < 0.01). Patients had significantly different complications including mild postoperative pain, hematoma, nipple necrosis, nipple paresthesias and effusions among the surgery subgroups (all P < 0.05). The estrogen level and the type of surgery were significantly different between the surgical recurrence and non-recurrence subgroups (P < 0.05). The difference in the thickness of glandular tissues upon the color Doppler ultrasound also reached a statistical significance between the two groups (P = 0.050). An elevated estrogen level was a factor leading to TAM failure. Among surgical patients, the thickness of glandular tissues, estrogen level, and type of surgery performed were risk factors for postoperative recurrence (all P < 0.05). CONCLUSION: Both treatment strategies can effectively treat gynecomastia, but different treatment methods can benefit different patients. TAM treatment is more beneficial than surgery for patients who cannot tolerate surgery, have a low estrogen level, and are clinical grade 1-2. Surgery treatment is better than TAM for patients of clinical grade 3. Different surgery options may lead to different complications. Patients with a greater glandular tissue thickness and a higher estrogen level were shown to have a higher risk of recurrence.

Polystyrene nanobeads exacerbate chronic colitis in mice involving in oxidative stress and hepatic lipid metabolism.

BACKGROUND: Nanoplastics (NPs) are omnipresent in our lives as a new type of pollution with a tiny size. It can enter organisms from the environment, accumulate in the body, and be passed down the food chain. Inflammatory bowel disease (IBD) is a nonspecific intestinal inflammatory disease that is recurrent and prevalent in the population. Given that the intestinal features of colitis may affect the behavior and toxicity of NPs, it is imperative to clarify the risk and toxicity mechanisms of NPs in colitis models. METHODS AND RESULTS: In this study, mice were subjected to three cycles of 5-day dextran sulfate sodium (DSS) exposures, with a break of 7 to 11 days between each cycle. After the first cycle of DSS exposure, the mice were fed gavagely with water containing 100 nm polystyrene nanobeads (PS-NPs, at concentrations of 1 mg/kg·BW, 5 mg/kg·BW and 25 mg/kg·BW, respectively) for 28 consecutive days. The results demonstrated that cyclic administration of DSS induced chronic inflammation in mice, while the standard drug "5-aminosalicylic acid (5-ASA)" treatment partially improved colitis manifestations. PS-NPs exacerbated intestinal inflammation in mice with chronic colitis by activating the MAPK signaling pathway. Furthermore, PS-NPs aggravated inflammation, oxidative stress, as well as hepatic lipid metabolism disturbance in the liver of mice with chronic colitis. CONCLUSION: PS-NPs exacerbate intestinal inflammation and injury in mice with chronic colitis. This finding highlights chronically ill populations' susceptibility to environmental hazards, which urgent more research and risk assessment studies.

Narirutin exerts anti-inflammatory activity by inhibiting NLRP3 inflammasome activation in macrophages.

Citrus peel has long been used in traditional medicine in Asia to treat common cold, dyspepsia, cough, and phlegm. Narirutin-a flavanone-7-O-glycoside-is the major flavonoid in citrus peel, and has anti-oxidative, anti-allergic, and anti-inflammatory activities. However, the anti-inflammatory mechanism of narirutin has not been fully elucidated. This study is aimed to investigate the effects of narirutin on the Nod-like receptor protein 3 (NLRP3)-mediated inflammatory response in vitro and in vivo, and determine the underlying mechanism. THP-1 differentiated macrophages and bone marrow-derived macrophages (BMDMs) were used for in vitro experiments, while dextran sulfate sodium (DSS)-induced colitis and alum-induced peritonitis mouse models were constructed to test inflammation in vivo. Narirutin suppressed secretion of interleukin (IL)-1ß and pyroptosis in lipopolysaccharide (LPS)/ATP-stimulated macrophages. Narirutin decreased the expression of NLRP3 and IL-1ß in the LPS-priming step through inhibition of NF-κB, MAPK and PI3K /AKT signaling pathways. Narirutin inhibited NLRP3-ASC interaction to suppress NLRP3 inflammasome assembly. Furthermore, oral administration of narirutin (300 mg/kg) alleviated inflammation symptoms in mice with peritonitis and colitis. These results suggest that narirutin exerts its anti-inflammatory activity by suppressing NLRP3 inflammasome activation via inhibition of the NLRP3 inflammasome priming processes and NLRP3-ASC interaction in macrophages.

First Report of Fusarium denticulatum Causing Chlorotic Leaf Distortion of Sweetpotato in China.

Sweetpotato (Ipomoea batatas) is one of the most important crops in China. To gain a clearer picture of the occurrence of diseases on sweetpotato, 50 fields (100 plants/field) were randomly surveyed in prominent sweetpotato growing areas of Lulong county, Hebei Province in the years 2021-2022. Plants showing chlorotic leaf distortion with mildly twisted young leaves and stunted vines were observed frequently. It was similar to the symptoms of chlorotic leaf distortion of sweetpotato (Clark et al. 2013). The incidence of disease with patch pattern ranged from 15% to 30%. Ten symptomatic leaves were excised, surface disinfested with 2% sodium hypochlorite for 1 min, rinsed three times in sterilized ddH2O, and cultured on potato dextrose agar (PDA) at 25°C. Nine fungal isolates were obtained. A pure culture of representative isolate FD10 obtained after serial hyphal tip transfer was examined for morphological and genetic characters. Colonies of isolate FD10 on PDA at 25°C were slow growing (4±0.1mm/day) with aerial, white-to-pink mycelium. Lobed colonies had greyish-orange pigmentation in reverse and conidia aggegated in false heads. Conidiophores were prostrate and short. Phialides were mostly monophialidic but occasionally polyphialidic. Polyphialidic openings often denticulate in a rectangular arrangement. Microconidia were abundant, long, oval to allantoid, mostly none or one septate, and 4.79 to 9.53 × 2.08 to 3.22 µm (n = 20). Macroconidia were fusiform to falcate with a beaked apical cell and a footlike basal cell, 3 to 5 septate, and 25.03 to 52.92 × 2.56 to 4.49 µm. Chlamydospores were absent. All in agreement with the morphology of Fusarium denticulatum (Nirenberg and O'Donnell 1998). Genomic DNA of isolate FD10 was extracted. The EF-1α and ß-tubulin genes were amplified and sequenced (O'Donnell and Cigelnik 1997; O'Donnell et al. 1998). The obtained sequences were deposited in GenBank (accession nos. OQ555191 and OQ555192). BLASTn revealed that those sequences showed 99.86% (EF-1α) and 99.93% (ß-tubulin) homology with the relative sequences of F. denticulatum type strain CBS407.97 (accession nos. MT011002.1 and MT011060.1), respectively. Furthermore, a neighbor-joining phylogenetic tree based on the EF-1α and ß-tubulin sequences revealed that the isolate FD10 clustered with F. denticulatum. Based on morphological characteristics and sequence analysis, the isolate FD10 associated with chlorotic leaf distortion of sweetpotato was identified as F. denticulatum. Pathogenicity tests were performed by immersing ten 25-cm-long vine-tip cuttings of cultivar Jifen 1 origin from tissue culture in a conidial suspension (1 × 106 conidia per ml) of isolate FD10. Vines immersed in sterile distilled water used as a control. All inoculated plants in 25-cm plastic pots were incubated in a climate chamber at 28℃ and 80% RH for two and half months and the control were incubated in a separate climate chamber. Nine inoculated plants developed chlorotic terminals, moderate interveinal chlorosis and slight leaf distortion. No symptoms were observed on the control plants. The pathogen was reisolated from inoculated leaves and matched the morphological and molecular characteristics of the original isolates, thus fulfilling Koch's postulates. To our knowledge, this is the first report of F. denticulatum causing chlorotic leaf distortion of sweetpotato in China. Its identification will promote the management of this disease in China.