Structural and functional characterization of a new thermophilic-like OYE from Aspergillus flavus

Old yellow enzymes (OYEs) have been proven as powerful biocatalysts for the asymmetric reduction of activated alkenes. Fungi appear to be valuable sources of OYEs, but most of the fungal OYEs are unexplored. To expand the OYEs toolbox, a new thermophilic-like OYE (AfOYE1) was identified from Aspergillus flavus strain NRRL3357. The thermal stability analysis showed that the T1/2 of AfOYE1 was 60 °C, and it had the optimal temperature at 45 °C. Moreover, AfOYE1 exhibited high reduction activity in a wide pH range (pH 5.5-8.0). AfOYE1 could accept cyclic enones, acrylamide, nitroalkenes, and α, β-unsaturated aldehydes as substrates and had excellent enantioselectivity toward prochiral alkenes (> 99% ee). Interestingly, an unexpected (S)-stereoselectivity bioreduction toward 2-methylcyclohexenone was observed. The further crystal structure of AfOYE1 revealed that the "cap" region from Ala132 to Thr182, the loop of Ser316 to Gly325, α short helix of Arg371 to Gln375, and the C-terminal "finger" structure endow the catalytic cavity of AfOYE1 quite deep and narrow, and flavin mononucleotide (FMN) heavily buried at the bottom of the active site tunnel. Furthermore, the catalytic mechanism of AfOYE1 was also investigated, and the results confirmed that the residues His211, His214, and Tyr216 compose its catalytic triad. This newly identified thermophilic-like OYE would thus be valuable for asymmetric alkene hydrogenation in industrial processes. KEY POINTS: A new thermophilic-like OYE AfOYE1 was identified from Aspergillus flavus, and the T1/2 of AfOYE1 was 60 °C AfOYE1 catalyzed the reduction of 2-methylcyclohexenone with (S)-stereoselectivity The crystal structure of AfOYE1 was revealedv.

Synergistic antifungal mechanism of cinnamaldehyde and nonanal against Aspergillus flavus and its application in food preservation

Aspergillus flavus colonization on agricultural products during preharvest and postharvest results in tremendous economic losses. Inspired by the synergistic antifungal effects of essential oils, the aims of this study were to explore the mechanism of combined cinnamaldehyde and nonanal (SCAN) against A. flavus and to evaluate the antifungal activity of SCAN loading into diatomite (DM). Shriveled mycelia were observed by scanning electron microscopy, especially in the SCAN treatment group. Calcofluor white staining, transmission electron microscopy, dichloro-dihydro-fluorescein diacetate staining and the inhibition of key enzymes in tricarboxylic acid cycle indicated that the antifungal mechanism of SCAN against A. flavus was related to the cell wall damage, reactive oxygen species accumulation and energy metabolism interruption. RNA sequencing revealed that some genes involved in antioxidation were upregulated, whereas genes responsible for cell wall biosynthesis, oxidative stress, cell cycle and spore development were significantly downregulated, supporting the occurrence of cellular apoptosis. In addition, compared with the control group, conidia production in 1.5 mg/mL DM/cinnamaldehyde, DM/nonanal and DM/SCAN groups were decreased by 27.16%, 48.22% and 76.66%, respectively, and the aflatoxin B1 (AFB1) contents decreased by 2.00%, 73.02% and 84.15%, respectively. These finding suggest that DM/SCAN complex has potential uses in food preservation.

m6A methyltransferase AflIme4 orchestrates mycelial growth, development and aflatoxin B1 biosynthesis in Aspergillus flavus

Aflatoxin B1 (AFB1), a highly toxic secondary metabolite produced by Aspergillus flavus, poses a severe threat to agricultural production, food safety and human health. The methylation of mRNA m6A has been identified as a regulator of both the growth and AFB1 production of A. flavus. However, its intracellular occurrence and function needs to be elucidated. Here, we identified and characterized a m6A methyltransferase, AflIme4, in A. flavus. The enzyme was localized in the cytoplasm, and knockout of AflIme4 significantly reduced the methylation modification level of mRNA. Compared with the control strains, ΔAflIme4 exhibited diminished growth, conidial formation, mycelial hydrophobicity, sclerotium yield, pathogenicity and increased sensitivity to CR, SDS, NaCl and H2O2. Notably, AFB1 production was markedly inhibited in the A. flavus ΔAflIme4 strain. RNA-Seq coupled with RT-qPCR validation showed that the transcriptional levels of genes involved in the AFB1 biosynthesis pathway including aflA, aflG, aflH, aflK, aflL, aflO, aflS, aflV and aflY were significantly upregulated. Methylated RNA immunoprecipitation-qPCR (MeRIP-qPCR) analysis demonstrated a significant increase in m6A methylation modification levels of these pathway-specific genes, concomitant with a decrease in mRNA stability. These results suggest that AflIme4 attenuates the mRNA stability of genes in AFB1 biosynthesis by enhancing their mRNA m6A methylation modification, leading to impaired AFB1 biosynthesis. Our study identifies a novel m6A methyltransferase AflIme4 and highlights it as a potential target to control A. flavus growth, development and aflatoxin pollution.

Dexamethasone relieves the inflammatory response caused by inguinal hernia meshes through miR-155

BACKGROUND

Inguinal hernia is a relatively common condition. Most patients with inguinal hernia require surgery. At present, mesh repair is one of the most effective methods to treat inguinal hernia, but insertion of the mesh can cause inflammation. Dexamethasone (DEX) can treat inflammation, but the mechanism by which DEX alleviates inflammation caused by inguinal hernia mesh placement remains unclear.

METHOD

We randomly divided rats into groups: negative control (NC), inguinal hernia (IH), polypropylene mesh (PM), DEX treatment, and miR-155 treatment groups. RT-qPCR was performed to determine the expression of miR-155. ELISA was implemented to determine the secretion of IL-1β, IL-6, and IL-18. Western blotting was used to detect caspase-1, JAK1, p-JAK1, STAT3, and p-STAT3 expression. A dual-luciferase reporter gene array identified a connection between miR-155 and JAK1.

RESULTS

The results revealed that the expression of miR-155, IL-1β, IL-6, and IL-18 was upregulated in the PM group. After DEX treatment, the secretion of miR-155, caspase-1, IL-1β, IL-6, and IL-18 decreased. Dual luciferase results confirmed that miR-155 induced the targeted downregulation of JAK1, while a miR-155 mimic reversed the therapeutic effect of DEX, and the expression levels of p-JAK1 and p-STAT3 increased.

CONCLUSION

DEX regulates the JAK1/STAT3 signaling pathway through miR-155 to relieve inflammation caused by inguinal hernia meshes.

Efficacy and safety of intrathecal pemetrexed for TKI-failed leptomeningeal metastases from EGFR+ NSCLC: an expanded, single-arm, phase II clinical trial

BACKGROUND

This study aimed to evaluate the efficacy and safety of intrathecal pemetrexed (IP) for treating patients with leptomeningeal metastases (LM) from non-small-cell lung cancer (NSCLC) who progressed from epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) treatment in an expanded, prospective, single-arm, phase II clinical study (ChiCTR1800016615).

PATIENTS AND METHODS

Patients with confirmed NSCLC-LM who progressed from TKI received IP (50 mg, day 1/day 5 for 1 week, then every 3 weeks for four cycles, and then once monthly) until disease progression or intolerance. Objectives were to assess overall survival (OS), response rate, and safety. Measurable lesions were assessed by investigator according to RECIST version 1.1. LM were assessed according to the Response Assessment in Neuro-Oncology (RANO) criteria.

RESULTS

The study included 132 patients; 68% were female and median age was 52 years (31-74 years). The median OS was 12 months (95% confidence interval 10.4-13.6 months), RANO-assessed response rate was 80.3% (106/132), and the most common adverse event was myelosuppression (n = 42; 31.8%), which reversed after symptomatic treatment. The results of subgroup analysis showed that absence of brain parenchymal metastasis, good Eastern Cooperative Oncology Group score, good response to IP treatment, negative cytology after treatment, and patients without neck/back pain/difficult defecation had longer survival. Gender, age, previous intrathecal methotrexate/cytarabine, and whole-brain radiotherapy had no significant influence on OS.

CONCLUSIONS

This study further showed that IP is an effective and safe treatment method for the EGFR-TKI-failed NSCLC-LM, and should be recommended for these patients in clinical practice and guidelines.

Mechanisms of methyl 2-methylbutyrate suppression on Aspergillus flavus growth and aflatoxin B1 biosynthesis

Aspergillus flavus and subsequently produced carcinogenic aflatoxins frequently contaminate postharvest food crops, resulting in a threat to global food safety. Chemical preservatives are currently the main antifungal agents. However, fungal resistance effect, biological toxicity, and environmental contamination limit their practical applications. The application of natural volatile organic compounds has great potential for controlling fungal and mycotoxin contamination of postharvest food crops. This study therefore investigated the antifungal and anti-aflatoxigenic activities of the volatile compound, methyl 2-methylbutyrate (M2M), against Aspergillus flavus and its potential mechanisms. M2M effectively inhibited A. flavus mycelia growth, with a minimum inhibitory concentration of 2.0 μL/mL. Moreover, M2M also suppressed aflatoxin production, sclerotia production, and the pathogenicity on peanut and corn flour. RNA-Seq results showed that 2899 differentially expressed genes (DEGs), and DEGs involved in ergosterol synthesis, cell wall structure, glycolysis, citric acid cycle, mitogen activated protein kinase signaling pathway, DNA replication, and aflatoxin biosynthesis, were down-regulated in A. flavus. Further studies showed that M2M strongly damaged the cell membrane and cell wall integrity, reduced ATP levels, and induced reactive oxygen species (ROS) accumulation and DNA damage. Notably, a GATA type zinc finger transcription factor, AfSreA (AFLA_132440), which is essential for A. flavus growth and aflatoxin production, was identified. The growth and aflatoxin yield in the ΔAfSreA strain decreased by 94.94 % and 71.82 %, respectively. Additionally, deletion of AfSreA destroyed cell wall integrity and decreased expressions of genes involved in aflatoxin biosynthesis. Taken together, our results identified the antifungal and anti-aflatoxigenic mechanisms of M2M against A. flavus, and confirmed the potential of M2M in protecting peanut and corn from fungal contamination.

Comprehensive analysis of aflatoxin B1 biosynthesis in Aspergillus flavus via transcriptome-wide m6A methylome response to cycloleucine

Aspergillus flavus and its toxic aflatoxins secondary metabolites contaminate food and grains, posing a severe threat to human health and leading to liver cancer. Here, we demonstrated that cycloleucine blocked aflatoxin B1 synthesis by inhibiting N6-methyladenosine (m6A) methylation modification of messenger RNA (mRNA). m6A Methylation Immunoprecipitation Sequencing (m6A MeRIP-Seq)-based comprehensive transcriptome-wide m6A profiling identified 102 differentially expressed genes that underwent m6A modification, of which 22 hypermethylated genes were downregulated and 49 hypomethylated genes were upregulated, suggesting a negative correlation between m6A methylation and gene expression. Notably, cycloleucine inhibited aflatoxin B1 production via multiple targets. The m6A sites of several key genes involved in the aflatoxin B1 biosynthesis pathway were significantly enriched in the coding sequence and around the stop codon, resulting in their downregulation. Furthermore, m6A methylation on genes related to the aflatoxin B1 biosynthesis pathway led to reduced mRNA stability. Cycloleucine inhibition of aflatoxin B1 production highlights its potential as an agent for removing mycotoxins in environmental pollution. ENVIRONMENTAL IMPLICATION: Aflatoxins, highly carcinogenic secondary metabolites produced by Aspergillus flavus, frequently contaminate crops such as peanut, corn, wheat and sesame leading to irreversible loss in the quality and yield of agricultural products and posing serious threats to food safety. Aflatoxins has also been linked to developmental delays and liver cancer in humans. In our study, 'monitoring aflatoxin concentrations and its bioaccumulation in organisms' has been conducted. The results demonstrated that aflatoxin production in A. flavus was completely blocked after cycloleucine treatment. Additionally, we demonstrated that inhibition of aflatoxin was linked to N6-methyladenosine methylation of multiple genes in aflatoxin biosynthesis pathway.

Functional Characterization of Aldehyde Dehydrogenase in Fusarium graminearum

Aldehyde dehydrogenase (ALDH), a common oxidoreductase in organisms, is an aldehyde scavenger involved in various metabolic processes. However, its function in different pathogenic fungi remains unknown. Fusarium graminearum causes Fusarium head blight in cereals, which reduces grain yield and quality and is an important global food security problem. To elucidate the pathogenic mechanism of F. graminearum, seven genes encoding ALDH were knocked out and then studied for their function. Single deletions of seven ALDH genes caused a decrease in spore production and weakened the pathogenicity. Furthermore, these deletions altered susceptibility to various abiotic stresses. FGSG_04194 is associated with a number of functions, including mycelial growth and development, stress sensitivity, pathogenicity, toxin production, and energy metabolism. FGSG_00139 and FGSG_11482 are involved in sporulation, pathogenicity, and SDH activity, while the other five genes are multifunctional. Notably, we found that FGSG_04194 has an inhibitory impact on ALDH activity, whereas FGSG_00979 has a positive impact. RNA sequencing and subcellular location analysis revealed that FGSG_04194 is responsible for biological process regulation, including glucose and lipid metabolism. Our results suggest that ALDH contributes to growth, stress responses, pathogenicity, deoxynivalenol synthesis, and mitochondrial energy metabolism in F. graminearum. Finally, ALDH presents a potential target and theoretical basis for fungicide development.

Prenatal exome sequencing analysis in fetuses with central nervous system anomalies

OBJECTIVE

To evaluate the utility of prenatal exome sequencing (pES) in fetuses with central nervous system (CNS) abnormalities.

METHODS

This was a retrospective cohort study of fetuses identified to have CNS abnormality on prenatal ultrasound and/or magnetic resonance imaging. All fetuses were first analyzed by chromosomal microarray analysis (CMA). Fetuses with a confirmed aneuploidy or causal pathogenic copy-number variant (CNV) on CMA did not undergo pES analysis and were excluded, while those with a negative CMA result were offered pES testing.

RESULTS

Of the 167 pregnancies included in the study, 42 (25.1%) were identified to have a pathogenic or likely pathogenic (P/LP) variant. The diagnostic rate was significantly higher in fetuses with a non-isolated CNS abnormality than in those with a single CNS abnormality (35.7% (20/56) vs 14.5% (8/55); P = 0.010). Moreover, when a fetus had three or more CNS abnormalities, the positive diagnostic rate increased to 42.9%. A total of 25/42 (59.5%) cases had de-novo mutations, while, in the remaining cases, mutations were inherited and carried a significant risk of recurrence. Families whose fetus carried a P/LP mutation were more likely to choose advanced pregnancy termination than those with a variant of uncertain significance, secondary/incidental finding or negative pES result (83.3% (25/30) vs 41.3% (38/92); P < 0.001).

CONCLUSION

pES improved the identification of genetic disorders in fetuses with CNS anomalies without a chromosomal abnormality or CNV identified on CMA, regardless of the number of CNS anomalies and presence of extracranial abnormality. We also demonstrated that pES findings can significantly impact parental decision-making. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Host response of Nicotiana benthamiana to the parasitism of five populations of root-lesion nematode, Pratylenchus coffeae, from China

In a recent survey of nematodes associated with tobacco in Shandong, China, the root-lesion nematode Pratylenchus coffeae was identified using a combination of morphology and molecular techniques. This nematode species is a serious parasite that damages a variety of plant species. The model plant benthi, Nicotiana benthamiana, is frequently used to study plant-disease interactions. However, it is not known whether this plant species is a host of P. coffeae. The objectives of this study were to evaluate the parasitism and pathogenicity of five populations of the root-lesion nematode P. coffeae on N. benthamiana.N. benthamiana seedlings with the same growth status were chosen and inoculated with 1,000 nematodes per pot. At 60 days after inoculation, the reproductive factors (Rf = final population densities (Pf)/initial population densities (Pi)) for P. coffeae in the rhizosphere of N. benthamiana were all more than 1, suggesting that N. benthamiana was a good host plant for P. coffeae.Nicotiana. benthamiana infected by P. coffeae showed weak growth, decreased tillering, high root reduction, and noticeable brown spots on the roots. Thus, we determined that the model plant N. benthamiana can be used to study plant-P. coffeae interactions.

Estragole Inhibits Growth and Aflatoxin Biosynthesis of Aspergillus flavus by Affecting Reactive Oxygen Species Homeostasis

A variety of essential oils and edible compounds have been widely recognized for their antifungal activity in recent years. In this study, we explored the antifungal activity of estragole from Pimenta racemosa against Aspergillus flavus and investigated the underlying mechanism of action. The results showed that estragole had significant antifungal activity against A. flavus, with a minimum inhibitory concentration of 0.5 μL/mL against spore germination. Additionally, estragole inhibited the biosynthesis of aflatoxin in a dose-dependent manner, and aflatoxin biosynthesis was significantly inhibited at 0.125 μL/mL. Pathogenicity assays showed that estragole had potential antifungal activity against A. flavus in peanut and corn grains by inhibiting conidia and aflatoxin production. Transcriptomic analysis showed that the differentially expressed genes (DEGs) were mainly related to oxidative stress, energy metabolism, and secondary metabolite synthesis following estragole treatment. Importantly, we experimentally verified reactive oxidative species accumulation following downregulation of antioxidant enzymes, including catalase, superoxide dismutase, and peroxidase. These results suggest that estragole inhibits the growth and aflatoxin biosynthesis of A. flavus by modulating intracellular redox homeostasis. These findings expand our knowledge on the antifungal activity and molecular mechanisms of estragole, and provide a basis for estragole as a potential agent against A. flavus contamination. IMPORTANCE Aspergillus flavus contaminates crops and produces aflatoxins, carcinogenic secondary metabolites which pose a serious threat to agricultural production and animal and human health. Currently, control of A. flavus growth and mycotoxin contamination mainly relies on antimicrobial chemicals, agents with side effects such as toxic residues and the emergence of resistance. With their safety, environmental friendliness, and high efficiency, essential oils and edible compounds have become promising antifungal agents to control growth and mycotoxin biosynthesis in hazardous filamentous fungi. In this study, we explored the antifungal activity of estragole from Pimenta racemosa against A. flavus and investigated its underlying mechanism. The results demonstrated that estragole inhibits the growth and aflatoxin biosynthesis of A. flavus by modulating intracellular redox homeostasis.

Synergistic effects of combined cinnamaldehyde and nonanal vapors against Aspergillus flavus

This study evaluated the synergistic antifungal effects of vapor-phase natural agents against Aspergillus flavus with an aim to prevent fungal contamination in agricultural products. Screening different combinations of natural antifungal vapor agents using the checkerboard assay revealed that the cinnamaldehyde and nonanal (S_CAN) blend could exert the strongest synergistic antifungal activities against A. flavus, with a minimum inhibitory concentration (MIC) of 0.03 μL/mL, which caused a 76 % decrease in fungal population compared to when each agent was used separately. Subsequent gas chromatography-mass spectrometry (GC/MS) analysis demonstrated that the cinnamaldehyde/nonanal combination was stable and no effects on their individual molecular structures. S_CAN at 2 × MIC completely inhibited the fungal conidia production and mycelial growth. The calcofluor white (CFW) and dichloro-dihydro-fluorescein diacetate (DCFH-DA) staining assays showed that S_CAN treatment could accelerate the destruction of cell wall integrity and accumulation of reactive oxygen species (ROS) in A. flavus. Moreover, pathogenicity assay indicated that in contrast to separate treatment with cinnamaldehyde or nonanal, S_CAN could cause a decrease in the production of A. flavus asexual spores and AFB1 on peanuts, which verified its potential synergistic activity against fungal propagation. In addition, S_CAN effectively preserves the organoleptic and nutritional properties of stored peanuts. Overall, our findings strongly indicated that the cinnamaldehyde/nonanal combination is a potentially significant antifungal agent against A. flavus contamination during the postharvest storage of peanuts.

AnAzf1 acts as a positive regulator of ochratoxin A biosynthesis in Aspergillus niger

Aspergillus niger produces genotoxic and carcinogenic ochratoxin A (OTA) that severely threatens human and animal health. Transcription factor Azf1 is essential in regulating fungal cell development and primary metabolism. However, its effect and mechanism on secondary metabolism are unclear. Here, we characterized and deleted a Azf1 homolog gene, An15g00120 (AnAzf1), in A. niger, which completely blocked OTA production, and repressed the OTA cluster genes, p450, nrps, hal, and bzip at the transcriptional level. The results indicated that AnAzf1 was a positive regulator of OTA biosynthesis. Transcriptome sequencing results showed that the AnAzf1 deletion significantly upregulated antioxidant genes and downregulated oxidative phosphorylation genes. Enzymes involved in reactive oxygen species (ROS) scavenging, including catalase (CAT) and peroxidase (POD) were increased, and the corresponding ROS levels were decreased. Upregulation of genes (cat, catA, hog1, and gfd) in the MAPK pathway and downregulation of genes in iron homeostasis were associated with decreased ROS levels, linking the altered MAPK pathway and iron homeostasis to lower ROS levels caused by AnAzf1 deletion. Additionally, enzymes including complex I (NADH-ubiquinone oxidoreductase), and complex V (ATP synthase), as well as ATP levels, were significantly decreased, indicating impaired oxidative phosphorylation caused by the AnAzf1-deletion. During lower ROS levels and impaired oxidative phosphorylation, OTA was not produced in ∆AnAzf1. Together, these results strongly suggested that AnAzf1 deletion blocked OTA production in A. niger by a synergistic interference of ROS accumulation and oxidative phosphorylation. KEY POINTS: • AnAzf1 positively regulated OTA biosynthesis in A. niger. • Deletion of AnAzf1 decreased ROS levels and impaired oxidative phosphorylation. • An altered MAPK pathway and iron homeostasis were associated with lower ROS levels.

The effect of surgical repair of hiatal hernia (HH) on pulmonary function: a systematic review and meta-analysis

PURPOSE

Hiatal hernia is renowned for the symptom of reflux, and few physicians associate a hiatal hernia with pulmonary issues. It is widely acknowledged that a hiatal hernia can be treated with surgery. However, less is known about how the surgical procedure would benefit pulmonary function. Thus, the aim of this study was to determine whether surgical repair can improve pulmonary function in patients with hiatal hernias.

METHODS

We registered the protocol on the PROSPERO (International Prospective Register of Systematic Reviews) platform (no. CRD42022369949). We searched the PubMed, Embase, Cochrane Library, and ClinicalTrials.gov databases for cohort studies that reported on the pulmonary function of patients with hiatal hernias. The quality of each cohort study was evaluated using the Newcastle-Ottawa scale (NOS). We then calculated mean differences (MDs) with 95% confidence intervals for these continuous outcomes. Each study's consistency was appraised using the I² statistic. The sensitivity analysis was performed using the trim-and-fill method. Publication bias was confirmed using the funnel plot visually and Egger regression test statistically.

RESULTS

A total of 262 patients from 5 cohorts were included in the meta-analysis. The quality evaluation revealed that, of these 5 papers, 3 received 8 NOS stars out of 9 stars, 1 received 9, and the other received 7, meaning all included cohort studies were of high quality. The results showed that surgical repair for a hiatal hernia significantly improved forced expiratory volume in 1 s (FEV1; weighted mean difference [WMD]:0.200; 95% CI 0.047-0.353; I² = 71.6%; P = 0.010), forced vital capacity (FVC; WMD: 0.242; 95% CI 0.161-0.323; I² = 7.1%; P = 0.000), and total lung capacity (TLC; WMD: 0.223; 95% CI 0.098-0.348; I² = 0.0%; P = 0.000) but had little effect on residual volume (RV; WMD: -0.028; 95% CI -0.096 to 0.039; I² = 8.7%; P = 0.411) and the diffusing capacity carbon monoxide (DLCO; WMD: 0.234; 95% CI -0.486 to 0.953; I² = 0.0%; P = 0.524).

CONCLUSION

For individuals with hiatal hernias, surgical repair is an efficient technique to improve respiratory function as measured by FEV1, FVC, and TLC.

Antagonistic Strain Bacillus halotolerans Jk-25 Mediates the Biocontrol of Wheat Common Root Rot Caused by Bipolaris sorokiniana

Common root rot caused by Bipolaris sorokiniana infestation in wheat is one of the main reasons for yield reduction in wheat crops worldwide. The bacterium strain JK-25 used in the current investigation was isolated from wheat rhizosphere soil and was later identified as Bacillus halotolerans based on its morphological, physiological, biochemical, and molecular properties. The strain showed significant antagonism to B. sorokiniana, Fusarium oxysporum, Fusarium graminearum, and Rhizoctonia zeae. Inhibition of B. sorokiniana mycelial dry weight and spore germination rate by JK-25 fermentation supernatant reached 60% and 88%, respectively. The crude extract of JK-25 was found, by Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS), to contain the surfactin that exerted an inhibitory effect on B. sorokiniana. The disruption of mycelial cell membranes was observed under laser scanning confocal microscope (LSCM) after treatment of B. sorokiniana mycelium with the crude extract. The antioxidant enzyme activity of B. sorokiniana was significantly reduced and the oxidation product malondialdehyde (MDA) content increased after treatment with the crude extract. The incidence of root rot was significantly reduced in pot experiments with the addition of JK-25 culture fermentation supernatant, which had a significant biological control effect of 72.06%. Its ability to produce siderophores may help to promote wheat growth and the production of proteases and pectinases may also be part of the strain's role in suppressing pathogens. These results demonstrate the excellent antagonistic effect of JK-25 against B. sorokiniana and suggest that this strain has great potential as a resource for biological control of wheat root rot strains.

Histone 2-Hydroxyisobutyryltransferase Encoded by Afngg1 Is Involved in Pathogenicity and Aflatoxin Biosynthesis in Aspergillus flavus

Aflatoxin, a carcinogenic secondary metabolite produced by Aspergillus flavus, is a significant threat to human health and agricultural production. Histone 2-hydroxyisobutyrylation is a novel post-translational modification that regulates various biological processes, including secondary metabolism. In this study, we identified the novel histone 2-hydroxyisobutyryltransferase Afngg1 in A. flavus, and explored its role in cell growth, development and aflatoxin biosynthesis. Afngg1 gene deletion markedly decreased lysine 2-hydroxyisobutyrylation modification of histones H4K5 and H4K8 compared with the control strain. Additionally, Afngg1 deletion inhibited mycelial growth of A. flavus, and the number of conidia and hydrophobicity were significantly decreased. Notably, aflatoxin B1 biosynthesis and sclerotia production were completely inhibited in the ΔAfngg1 strain. Furthermore, the pathogenicity of the ΔAfngg1 strain infecting peanut and corn grains was also diminished, including reduced spore production and aflatoxin biosynthesis compared with A. flavus control and Afngg1 complementation strains. Transcriptome analysis showed that, compared with control strains, differentially expressed genes in ΔAfngg1 were mainly involved in chromatin remodelling, cell development, secondary metabolism and oxidative stress. These results suggest that Afngg1 is involved in histone 2-hydroxyisobutyrylation and chromatin modification, and thus affects cell development and aflatoxin biosynthesis in A. flavus. Our results lay a foundation for in-depth research on the 2-hydroxyisobutyrylation modification in A. flavus, and may provide a novel target for aflatoxin contamination prevention.

Putative C2H2 Transcription Factor AflZKS3 Regulates Aflatoxin and Pathogenicity in Aspergillus flavus

Aflatoxin is a carcinogenic secondary metabolite that poses a serious threat to human and animal health. Some C₂H₂ transcription factors are associated with fungal growth and secondary metabolic regulation. In this study, we characterized the role of AflZKS3, a putative C₂H₂ transcription factor based on genome annotation, in the growth and aflatoxin biosynthesis of A. flavus and explored its possible mechanisms of action. Surprisingly, the protein was found to be located in the cytoplasm, and gene deletion in A. flavus resulted in defective growth and conidia formation, as well as increased sensitivity to the fluorescent brightener Calcofluor white, Congo red, NaCl, and sorbitol stress. Notably, the biosynthesis of aflatoxin B₁ was completely inhibited in the ΔAflZKS3 deletion strain, and its ability to infect peanut and corn seeds was also reduced. RNA sequencing showed that differentially expressed genes in the ΔAflZKS3 strain compared with the control and complementation strains were mainly associated with growth, aflatoxin biosynthesis, and oxidative stress. Thus, AflZKS3 likely contributes to growth, cell development, and aflatoxin synthesis in A. flavus. These findings lay the foundation for a deeper understanding of the roles of C₂H₂ transcription factors in A. flavus and provide a potential biocontrol target for preventing aflatoxin contamination.

Quantitative Acetylome Analysis of Soft Wheat Seeds during Artificial Ageing

Lysine acetylation (Kac) is a protein post-translational modification (PTM) widely found in plants that plays vital roles in metabolic pathways. Although seed germination and development are regulated by Kac, its potential function in seed ageing remains to be investigated. Our preliminary study demonstrated that Kac levels were altered during wheat seed artificial ageing. However, its specific role in this process still needs to be elucidated. Here, we performed quantitative acetylation proteomics analysis of soft wheat seeds with different germination rates during artificial ageing. A total of 175 acetylation proteins and 255 acetylation modification sites were remarkably changed. The differentially acetylated proteins were enriched in metabolism; response to harsh intracellular environment, such as ROS; protein storage and processing. Notably, expression, point mutation to mimic Kac by K to Q mutation at K80 and K138, protein purification and enzyme activity detection revealed that the Kac of ROS-scavenging glutathione transferase attenuated its activity, indicating that the defense ability of wheat seeds to stress gradually diminished, and the ageing process was inevitable. Collectively, our data provide a basis for further understanding the roles of Kac in seed ageing and might aid in the development of new techniques to prolong seed viability and food quality.

Afper1 contributes to cell development and aflatoxin biosynthesis in Aspergillus flavus

Aspergillus flavus contaminates crops and produces carcinogenic aflatoxins that pose severe threat to food safety and human health. To identify potential targets to control aflatoxin contamination, we characterized a novel Afper1 protein, which regulates cell development and secondary metabolite biosynthesis in A. flavus. Afper1 is localized in the nucleus and is required for hyphal growth, conidial and sclerotial production, and responses to osmotic stress and essential oils such as cinnamaldehyde and thymol. More importantly, aflatoxin production was impaired in the Afper1 deletion mutant. Proteomics analysis revealed that extracellular hydrolases and proteins involved in conidial development, endoplasmic reticulum (ER) homeostasis, and aflatoxin biosynthesis were differentially regulated in ΔAfper1. Unexpectedly, enzymes participated in reactive oxygen species (ROS) scavenging, including catalase (catA, catB) and superoxide dismutase (sodM) were significantly downregulated, and the ROS accumulation and sensitivity to hydrogen peroxide were confirmed experimentally. Additionally, Afper1 deletion significantly upregulated heterochromatin protein HepA and downregulated acetyltransferases involved in heterochromatin formation. Accompanying ROS accumulation and chromatin remodeling, proteins related to aflatoxins, ustiloxin B and gliotoxin were downregulated. These results implied that Afper1 deletion affected chromatin remodeling and disturbed ER homeostasis, leading to ROS accumulation, and ultimately resulting in defective growth and impaired secondary metabolite biosynthesis.

The association of coffee consumption with the risk of osteoporosis and fractures: a systematic review and meta-analysis

To elucidate the association of coffee and bone health would help fracture risk reduction via dietary intervention. Although those who had higher coffee consumption were less likely to have osteoporosis, the associations between coffee consumption and fracture risk need further investigations with better study designs.

INTRODUCTION

The associations between coffee consumption and the risk of osteoporosis and fracture remain inconclusive. We aimed to better quantify these associations by conducting meta-analyses of observational studies.

METHODS

Relevant studies were systematically searched on PubMed, Web of Science, Cochrane library, and Embase Database up to November 25, 2021. The odds ratio (OR) or relative risk (RR) with 95% confidence intervals (CI) was pooled and a dose-response analysis was performed.

RESULTS

Four studies with 7114 participants for osteoporosis and thirteen studies with 391,956 participants for fracture incidence were included in the meta-analyses. High versus low coffee consumption was associated with a lower risk of osteoporosis [pooled OR (95% CI): 0.79 (0.65-0.92)], while it was non-significantly associated with fracture incidence [pooled OR (95% CI): 0.86 (0.67-1.05) at hip and 0.89 (0.42-1.36) at non-hip]. A non-linear association between the level of coffee consumption and hip fracture incidence was shown (P = 0.004). The pooled RR (95% CI) of hip fracture risk in those who consumed 1, 2-3, 4, and ≥ 9 cups of coffee per day was 0.92 (0.87-0.97), 0.89 (0.83-0.95), 0.91 (0.85-0.98), and 1.10 (0.76-1.59), respectively. The significance in the association between coffee consumption and the hip fracture incidence decreased in those studies that had larger sample size, higher quality, and more adjustments.

CONCLUSIONS

A dose-dependent relationship may exist between coffee consumption and hip fracture incidence. The effect of high versus low coffee consumption was influenced by study designs. Further studies with dedicated designs are needed to confirm the independent effects of coffee consumption on bone health.

Insights into the Underlying Mechanism of Ochratoxin A Production in Aspergillus niger CBS 513.88 Using Different Carbon Sources

Aspergillus niger produces carcinogenic ochratoxin A (OTA), a serious food safety and human health concern. Here, the ability of A. niger CBS 513.88 to produce OTA using different carbon sources was investigated and the underlying regulatory mechanism was elucidated. The results indicated that 6% sucrose, glucose, and arabinose could trigger OTA biosynthesis and that 1586 differentially expressed genes (DEGs) overlapped compared to a non-inducing nutritional source, peptone. The genes that participated in OTA and its precursor phenylalanine biosynthesis, including pks, p450, nrps, hal, and bzip, were up-regulated, while the genes involved in oxidant detoxification, such as cat and pod, were down-regulated. Correspondingly, the activities of catalase and peroxidase were also decreased. Notably, the novel Gal4-like transcription factor An12g00840 (AnGal4), which is vital in regulating OTA biosynthesis, was identified. Deletion of AnGal4 elevated the OTA yields by 47.65%, 54.60%, and 309.23% using sucrose, glucose, and arabinose as carbon sources, respectively. Additionally, deletion of AnGal4 increased the superoxide anion and H₂O₂ contents, as well as the sensitivity to H₂O₂, using the three carbon sources. These results suggest that these three carbon sources repressed AnGal4, leading to the up-regulation of the OTA biosynthetic genes and alteration of cellular redox homeostasis, ultimately triggering OTA biosynthesis in A. niger.

AB0066 EFFECT AND MECHANISM OF QINXITONG ON BIOLOGICAL BEHAVIOR OF SYNOVIAL FIBROBLASTS IN RHEUMATOID ARTHRITIS

Background

Chinese medicine has been used widely for the treatment of RA for a long history in China. The Fifth Hospital of Xi’an has treated patients of RA with QinXiTong(QXT) for 40 years which is mainly based on the water extract from Caulis Sinomenii(CS). However, the molecular mechanism of its anti-rheumatism effect remains unclear.

Objectives

To investigate the effects of Qinxitong on proliferation, apoptosis, migration and invasion of synovial fibroblasts in rheumatoid arthritis and its mechanism.

Methods

Taking rheumatoid arthritis synovial fibroblast cell line MH7A as the research object. The cells were divided into four groups according to the different dosage of Qinxitong intervention, namely control group, low dose group (QXT-20), medium dose group (QXT-50) and high dose group (QXT-100). CCK-8 assay was used to detect cell proliferation, flow cytometry was used to detect cell apoptosis, Transwell assay was used to detect cell migration and invasion, and Western blotting was used to detect total Erk protein (t-Erk) and phosphorylated Erk protein (p-Erk) expression levels.

Results

CCK-8 assay showed that Qinxitong could inhibit the proliferation of MH7A cells, compared with the control group, cell proliferation in QXT-50 and QXT-100 groups was significantly reduced (p<0.05) after 24h, 48, and 72h intervention, the effect of QXT-100 was even more significant (p<0.001); flow cytometry showed that QXT could promote apoptosis of MH7A cells, compared with the control group, the apoptosis rate of QXT-50 and QXT-100 groups was significantly increased (p<0.05); Transwell assay showed that QXT could inhibit the migration and invasion of MH7A cells, compared with the control group, the QXT-50 and QXT-100 groups showed significantly higher inhibition of migration and invasion of MH7A cells (p<0.05); Western blotting showed that QXT could reduced p-Erk expression level, compared with the control group, the decrease of p-Erk expression level in QXT-50 and QXT-100 groups was statistically significant (p<0.001).

Conclusion

Qinxitong can inhibit the proliferation, promote apoptosis, inhibit migration and invasion of rheumatoid arthritis synovial fibroblasts by regulating Erk signaling pathway, providing scientific basis for clinical application of Qixintong.

Disclosure of Interests

None declared

Lysine 2-hydroxyisobutyrylation orchestrates cell development and aflatoxin biosynthesis in Aspergillus flavus

Lysine 2-hydroxyisobutyrylation (K_hib ) is a recently identified post-translational modifications (PTM) that regulates numerous cellular metabolic processes. In pathogenic microorganism, although glycolysis and fungal virulence are regulated by K_hib , its potential roles in fungi remains to be elusive. Our preliminary results showed that levels of K_hib fluctuate over time in Aspergillus flavus, which frequently contaminates crops and produces carcinogenic aflatoxins. However, the perception of K_hib function in A. flavus is limited, especially in mycotoxin-producing strains. Here, we performed a comprehensive analysis of K_hib in A. flavus, and 7156 K_hib sites were identified in 1473 proteins. Notably, we demonstrated that K_hib of AflM, a key enzyme in aflatoxin biosynthesis, affected conidia production and sclerotia formation. Furthermore, aflM deletion impaired aflatoxin biosynthesis, and more importantly, strains in which K_hib was mimicked by K to T mutation at K49, K179 and K180 sites showed reduced aflatoxin production compared with wild type and ΔaflM complementation strains. These results indicate that K_hib at these sites of AflM negatively regulates aflatoxin biosynthesis in A. flavus. In summary, our study revealed the potential roles of K_hib in A. flavus, and particularly shed light on a new way to regulate aflatoxin production via K_hib . This article is protected by copyright. All rights reserved.

Utilizing phenotypic characteristics of metastatic brain tumors to improve the probability of detecting circulating tumor DNA from cerebrospinal fluid in non-small-cell lung cancer patients: development and validation of a prediction model in a prospective cohort study

Background

Circulating tumor DNA (ctDNA) in cerebrospinal fluid (CSF) has become a promising surrogate for genomic profiling of central nervous system tumors. However, suboptimal ctDNA detection rates from CSF limit its clinical utility. Thus precise screening of suitable patients is needed to maximize the clinical benefit.

Patients and methods

Between February 2017 and December 2020, 66 newly diagnosed non-small-cell lung cancer (NSCLC) patients with brain parenchymal metastases were prospectively enrolled as a training cohort and 30 additional patients were enrolled as an external validation cohort. CSF samples and matched primary tumor tissues were collected before treatment and subjected to next-generation sequencing (NGS). The imageological characteristics of patients’ brain tumors were evaluated by radiologists using enhanced magnetic resonance imaging images. The clinical and imageological characteristics were evaluated by complete subsets regression, Akaike information criteria, and Bayesian information criteria methods to establish the prediction model. A nomogram was then built for CSF ctDNA detection prediction.

Results

The somatic mutation detection rate of genes covered by our targeted NGS panel was significantly lower in CSF ctDNA (59.09%) than tumor tissue (91.84%). The T_size (diameter of the largest intracranial lesion) and LVD_min (minimum lesion–ventricle distance for all intracranial lesions) were significantly associated with positive CSF ctDNA detection, and thus, were selected to establish the prediction model, which achieved an area under the ROC curve (AUC) of 0.819 and an accuracy of 0.800. The model’s predictive ability was further validated in the independent external cohort (AUC of 0.772, accuracy of 0.767) and by internal cross-validation. The CSF ctDNA detection rate was significantly improved from 58.18% (32/55) to 81.81% (27/33) in patients after model selection (P = 0.022).

Conclusions

This study developed a regression model to predict the probability of detecting CSF ctDNA using the phenotypic characteristics of metastatic brain lesions in NSCLC patients, thus, maximizing the benefits of CSF liquid biopsies.

•

Intracranial tumor size and distance to nearest ventricle were significantly correlated with positive CSF ctDNA detection.

•

A prediction model incorporating T_size and LVD_min was developed and validated to evaluate the odds of CSF ctDNA positivity.

•

The CSF ctDNA detection rate was significantly improved in patients after model selection.

Nomogram to predict survival of patients with advanced and metastatic pancreatic Cancer

BACKGROUND

Nomograms are rarely employed to estimate the survival of patients with advanced and metastatic pancreatic cancer (PC). Herein, we developed a comprehensive approach to using a nomogram to predict survival probability in patients with advanced and metastatic PC.

METHODS

A total of 323 patients with advanced and metastatic PC were identified from the Chinese People's Liberation Army (PLA) General Hospital. A baseline nomogram was constructed using baseline variables of 323 patients. Additionally, 233 patients, whose tumors showed initial responses to first-line chemotherapy, were enrolled in the chemotherapy response-based model. 128 patients and 108 patients with advanced and metastatic PC from January 2019 to April 2021 were selected for external validating baseline model and chemotherapy response-based model. The 1-year and 2-year survival probability was evaluated using multivariate COX regression models. The discrimination and calibration capacity of the nomograms were assessed using C-statistic and calibration plots. The predictive accuracy and net benefit of the nomograms were evaluated using ROC curve and DCA, respectively.

RESULTS

In the baseline model, six variables (gender, KPS, baseline TB, baseline N, baseline WBC and baseline CA19-9) were used in the final model. In the chemotherapy response-based model, nine variables (KPS, gender, ascites, baseline N, baseline CA 19-9, baseline CEA, change in CA 19-9 level at week, change in CEA level at week and initial response to chemotherapy) were included in the final model. The C-statistics of the baseline nomogram and the chemotherapy response-based nomogram were 0.67 (95% CI, 0.62-0.71) and 0.74 (95% CI, 0.69-0.77), respectively.

CONCLUSION

These nomograms were constructed to predict the survival probability of patients of advanced and metastatic PC. The baseline model and chemotherapy response-based model performed well in survival prediction.

The analysis of osteosarcopenia as a risk factor for fractures, mortality, and falls

Osteosarcopenia is defined as the concomitant occurrence of sarcopenia and osteoporosis/osteopenia. This study aimed to clarify whether osteosarcopenia implies a greater risk of fractures, mortality, and falls and to draw attention to osteosarcopenia.

INTRODUCTION

Osteosarcopenia, which is characterized by the co-existence of osteoporosis/osteopenia and sarcopenia, is one of the most challenging geriatric syndromes. However, the association between osteosarcopenia and the risk of falls, fractures, disability, and mortality is controversial.

METHODS

We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials, from their inception to March 18, 2021, for cohort studies on the relationship between osteosarcopenia and fractures, falls, and mortality. Two reviewers independently extracted data and assessed study quality. A pooled analysis was performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs) using fixed or random-effects models.

RESULTS

Eight cohort studies including 19,836 participants showed that osteosarcopenia significantly increased the risk of fracture (OR 2.46, 95% CI 1.83-3.30, P_{heterogeneity} = 0.006, I² = 63.0%), three cohort studies involving 2601 participants indicated that osteosarcopenia significantly increased the risk of mortality (OR 1.66, 95% CI 1.23-2.26, P_{heterogeneity} = 0.214, I² = 35.2%), and three cohort studies involving 3144 participants indicated that osteosarcopenia significantly increased the risk of falls (OR 1.62, 95% CI 1.28-2.04, P_{heterogeneity} = 0.219, I² = 34.1%). No publication bias existed among the studies regarding the association between osteosarcopenia and fractures. The findings were robust according to the subgroup and sensitivity analyses.

CONCLUSIONS

This pooled analysis demonstrated that osteosarcopenia significantly increased the risk of fractures, falls, and mortality, thus highlighting its relevance in daily life. Therefore, we suggest that elderly persons should be aware of the risks associated with osteosarcopenia.

Potential probiotics Lactobacillus casei K11 combined with plant extracts reduce markers of type 2 diabetes mellitus in mice

AIMS

Probiotics and plant extracts have been used to prevent the development of type 2 diabetes mellitus (T2DM). The study aimed to explore the effect of the interaction between potential probiotics and bitter gourd extract (BGE) or mulberry leaf extract (MLE) on T2DM.

METHODS AND RESULTS

Potential probiotics were tested for their gastrointestinal tract viability and growth situation combined with BGE and MLE in vitro. The diabetes model was constructed in C57BL/6 mice, and the potential effect and mechanism of regulating blood glucose were verified. Hematoxylin-eosin staining (HE), gas chromatography (GC), ELISA, and RT-PCR were also used for analysis. The results showed that Lactobacillus casei K11 had outstanding gastrointestinal tract viability and growth situation with plant extracts. Administration of L. casei K11 combined with BGE and MLE significantly reduced blood glucose levels and ameliorated insulin resistance in diabetic mice than the administration of Lactobacillus paracasei J5 combined with BGE and MLE. Moreover, in L. casei K11 combined with BGE and MLE groups, lipid metabolism, oxidative stress, and proinflammatory cytokine levels were regulated. Furthermore, the results indicated that L. casei K11 combined with BGE and MLE improved free fatty acid receptor 2 (FFAR2) upregulation, glucagon-like peptide-1 (GLP-1) secretion, and short-chain fatty acid (SCFA) levels.

CONCLUSIONS

These findings showed that L. casei K11 combined with BGE and MLE modified the SCFA-FFAR2-GLP-1 pathway to improve T2DM.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study identified a new modality for evaluating interactions between potential probiotics and plant extracts. Our findings revealed that L. casei K11 combined with BGE and MLE significantly promoted the SCFA-FFAR2-GLP-1 pathway to inhibit T2DM.

Sub3 inhibits Aspergillus flavus growth by disrupting mitochondrial energy metabolism, and has potential biocontrol during peanut storage

BACKGROUND

Aspergillus flavus, a saprophytic fungus, is regularly detected in oil-enriched seeds. During colonization, this organism releases aflatoxins that pose a serious risk to food safety and human health. Therefore, an eco-friendly biological approach to inhibit the pathogen is desirable.

RESULTS

Experimental results indicated that A. flavus spores could not germinate in potato dextrose broth culture medium, when the concentration of Sub3 exceeded 0.15 g L^-1 . Morphological evaluation performed by flow cytometry and scanning electron microscopy indicated that spores were shrunken and pitted following Sub3 exposure. Physiological assessment using propidium iodide, 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolocarbocyanine iodide, 2,7-dichlorodihydrofluorescein diacetate and 4',6-diamidino-2-phenylindole staining revealed damaged cell membranes, decreased mitochondrial membrane potential, increased intracellular reactive oxygen species levels, and elevated large nuclear condensation and DNA fragmentation. Moreover, mitochondrial dehydrogenase activity was reduced by 29.42% and 45.48% after treatment with 0.1 and 0.15 g L^-1 Sub3, respectively. Additionally, colonization capacity in peanut was significantly decreased, and the number of spores on seeds treated with Sub3 was decreased by 26.86% (0.1 g L^-1 ) and 77.74% (0.15 g L^-1 ) compared with the control group.

CONCLUSION

Sub3 likely inhibits A. flavus by crossing the cell wall and targeting the cell membrane, disrupting mitochondrial energy metabolism, and inducing DNA damage, leading to spore death. Thus, Sub3 may provide a useful biocontrol strategy to control A. flavus growth in peanuts. © 2020 Society of Chemical Industry.

Bedaquiline in the treatment of multidrug- and extensively drug-resistant tuberculosis in China

BACKGROUND: Multidrug- and extensively drug-resistant tuberculosis (MDR/XDR-TB) continues to be a challenge in China. Bedaquiline (BDQ) is associated with accelerated sputum culture conversion and favourable treatment outcomes when added to a preferred background regimen. This post-hoc study aimed to assess the outcomes of BDQ treatment in Chinese patients with MDR/XDR-TB.METHODS: Data from 51 Chinese patients who participated in a global Phase 2, open-label, single-arm study (TMC207-C209) were analysed for effectiveness and safety of the BDQ-containing regimen.RESULTS: During the 24-week BDQ treatment, adverse events (AEs) occurred in 48 patients (94.1%), with the most common AE being hyperuricemia. Drug-induced liver injury (DILI) was reported in 13 patients (25.5%); serious DILI was reported in one patient (2.0%). Seven (13.7%) AEs were considered to be possibly related to BDQ by the investigators. Only one Grade 1 QTc prolongation was reported; no QTcF >500 ms was reported. One death occurred after BDQ treatment due to progressive TB. The median time to sputum culture conversion was 85 days based on the 24-week data. The sputum culture conversion rate was 82% at 24 weeks and 78% at 120 weeks; 66% of patients achieved a cure.CONCLUSIONS: BDQ was well-tolerated and effective for treating MDR-TB among Chinese patients.

Structural analysis of pulsed magnets considering interface characteristics

The aim of traditional designs of pulsed magnets is to keep the von-Mises stress on the midplane less than the ultimate tensile strength of materials. However, recently failed high-field experiments showed that some short circuits occurred at the magnet end, which is most possibly caused by the axial displacement of wires. This indicates that the former design is inadequate and accurate axial mechanical analysis of magnets is necessary. In this paper, a finite element model of pulsed magnets considering interface characteristics is proposed. Both the contact status and interfacial friction between the conductor layers and reinforcements can be accounted for Simulations are conducted with a failed 95 T dual-coil prototype, which was originally designed with the self-developed Pulsed Magnet Design Software (PMDS) software. The simulation results show that all the originally expected separations calculated by the PMDS software disappear due to the compression. This makes the calculated maximal von-Mises stress of the inner four reinforcement layers about 600 MPa less than the former designs. The influence of the interfacial friction is also presented. Besides, the simulations show that the maximum axial displacement at the magnet end is up to 8 mm at the designed peak field, which is deadly to the insulations. Hence, we suggest that the axial displacement at the magnet end should also be one design objective of pulsed magnets. At last, the factors affecting the axial displacement are analyzed.

Identification and characterization of long non-coding RNAs as competing endogenous RNAs in the cold stress response of Triticum aestivum

Long non-coding RNAs (lncRNAs) play important roles in plant development and stress responses. MicroRNAs (miRNAs) are involved in transcriptional and post-transcriptional gene regulation. It is not clear how lncRNA-mediated plant responses to cold stress and how lncRNAs, miRNAs and target mRNAs cooperate subject to the competing endogenous RNA (ceRNA). We interpreted the function of lncRNAs in the winter wheat cultivar Dongnongdongmai 1 (Dn1). A total of 9970 putative lncRNAs were initially identified from three Dn1 lncRNA libraries (5 °C, -10 °C and -25 °C) using high-throughput sequencing. Among the 14,626 genes detected via weighted gene co-expression network analysis, 7435 lncRNAs were co-expressed with 7191 mRNAs. We found six modules related to cold resistance in the lncRNA-mRNA weighted co-expression network, and the functions of mRNAs were similar in each module. Antioxidant systems and hormones played important roles in low-temperature responses. RNA sequencing analysis revealed that interactions between the 384 lncRNAs and 70 miRNAs were required for ceRNA activity. According to ceRNA activity, 225 lncRNAs, 60 miRNAs and 621 target mRNAs were involved in the regulatory networks of the cold stress response. Notably, a conserved region was found in the complementary regions of lncRNAs and miR164/408 but had reverse expression trends in the ceRNA network. Our results reveal possible roles of lncRNAs-mRNAs in the regulatory networks associated with tolerance to low temperature and provide useful information for more strategic use of genomic resources in wheat breeding.

Copper-catalyzed 1,1-alkynylalkylation of alkynes: access toward conjugated enynes

A copper-catalyzed 1,1-alkynylalkylation of alkynes with α-haloacetamides for the construction of conjugated enynes has been developed.

Are left ventricular muscle area and radiation attenuation associated with overall survival in advanced pancreatic cancer patients treated with chemotherapy?

AIM

To evaluate whether cardiac muscle area and radiation attenuation, determined using pre-chemotherapy computed tomography (CT), are associated with therapeutic response and overall survival (OS) in chemotherapy-treated advanced pancreatic cancer (APC) patients.

MATERIALS AND METHODS

Ninety-eight chemotherapy-treated APC patients who underwent pre-chemotherapy CT between 2009 and 2018 were considered. Left ventricular muscle area (LVMA) and left ventricular muscle radiation attenuation (LVMRA) were measured using pre-chemotherapy arterial-phase CT. OS and progression-free survival (PFS) were analysed using Kaplan-Meier curves. Univariate and multivariate Cox regression analyses were performed to analyse potential factors affecting OS and PFS.

RESULTS

Patients with low LVMRA, low LVMA at baseline CT, and multiple metastases had a significantly shorter median OS than patients with high LVMRA, high LVMA, and without multiple metastases (8.8 versus 14 months, p=0.017; 12.2 versus 18.1 months, p=0.038; 7.3 versus 13.5 months, p<0.001, respectively). Patients with low LVMRA and distant metastasis had a shorter median PFS than patients with high LVMRA and those without distant metastasis (4.9 versus 8.3 months, p=0.032; 5.4 versus 9.9 months, p=0.002, respectively). Moreover, the mean LVMRA was the highest in the partial response group (p=0.028).

CONCLUSION

LVMRA could well predict PFS and OS in chemotherapy-treated APC patients.

Combined therapy of infusion of DC from rats with higher expression of IDO and CD40L on rejection post heart transplantation

OBJECTIVE

Indoleamine 2, 3-dioxygenase (IDO) can inhibit rejection of graft via inducing T cell apoptosis. CD40L monoclonal antibody (mAb) inhibits T cell activation. However, the effects of the combination of infusion of dendritic cell (DC) from IDO over-expressed donor mice and CD40L mAb on the treatment of graft rejection after heart transplantation have not been reported.

MATERIALS AND METHODS

Allogeneic heart transplantation mouse model was established. Recipient mice were divided into three groups, including control group, IDO group (in which DC donors received adenoviral vector of IDO) and combined therapy group (which received both IDO over-expressed DC infusion and CD40L mAb injection post transplantation). Survival time and cardiac function were observed, with IDO expression being quantified. Flow cytometry (FCM) was used to analyze T cell apoptosis, while enzyme linked immunosorbent assay (ELISA) was adopted to test the levels of interferon-γ (IFN-γ), interleukin-2 (IL-2), interleukin-10 (IL-10) and interleukin-6 (IL-6).

RESULTS

IDO expression was significantly elevated in both IDO and combined therapy groups, with enhanced T cell apoptosis compared to control group (p < 0.05). Both groups had better survival time and cardiac functions compared to control group, along with increased IL-10/IL-6 expression and suppressed INF-γ and IL-2 expression (p < 0.05). However, combined therapy had a better efficiency compared to IDO group (p < 0.05).

CONCLUSIONS

Combined therapy of high IDO expressed mouse DC perfusion with CD40L mAb can elongate the survival time of recipient heart and inhibit rejection reaction via facilitating T cell apoptosis. Meanwhile, combined therapy could also regulate the expression of some immune suppressant factors and mediate the Th1/Th2 cytokine balance.

Expression and purification of recombinant puroindoline A protein in Escherichia coli and its antifungal effect against Aspergillus flavus

Aspergillus flavus is the main cause of postharvest agricultural commodity loss. In this study, puroindoline A (PINA) protein was expressed in Escherichia coli, purified, and its antifungal properties against A. flavus were characterized. Sodium dodecyl sulfate polyacrylamide gel electrophoresis showed that the molecular weight of the recombinant PINA protein was approximately 44 kDa. PINA exerted a powerful antifungal effect against A. flavus at 42.42 μg/mL on potato dextrose agar culture medium. Flow cytometry and scanning electron microscopy revealed that the spore morphology was damaged by PINA exposure; spores were depressed and broken, suggesting that the cell wall was impaired. Transmission electron microscopy and propidium iodide staining illustrated significant changes in intracellular spore structure, indicating cell membrane damage. 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolocarbocyanine iodide staining indicated decreased mitochondrial membrane potential. Large nuclear condensation and DNA fragmentation were detected by 4',6-diamidino-2-phenylindole staining. The expression of genes related to the cell wall, cell membrane, and spore germination significantly changed in PINA-treated cells; this illustrated the probable mode of PINA action on A. flavus through cell wall destruction and triggered cell membrane, mitochondrial, and DNA damage leading to cell death. The antifungal mechanism of wheat PINA protein on A. flavus has been demonstrated in this study, and has potential application in preventing postharvest loss in the agricultural industry.

Notch3 signaling activation in smooth muscle cells promotes extrauterine growth restriction-induced pulmonary hypertension

BACKGROUND AND AIMS

Early postnatal life is a critical developmental period that affects health of the whole life. Extrauterine growth restriction (EUGR) causes cardiovascular development problems and diseases, including pulmonary arterial hypertension (PAH). PAH is characterized by proliferation, migration, and anti-apoptosis of pulmonary artery smooth muscle cells (PASMCs). However, the role of PASMCs in EUGR has not been studied. Thus, we hypothesized that PASMCs dysfunction played a role in EUGR-induced pulmonary hypertension.

METHODS AND RESULTS

Here we identified that postnatal nutritional restriction-induced EUGR rats exhibited an elevated mean pulmonary arterial pressure and vascular remodeling at 12 weeks old. PASMCs of EUGR rats showed increased cell proliferation and migration features. In EUGR-induced PAH rats, Notch3 signaling was activated. Relative mRNA and protein expression levels of Notch3 intracellular domain (Notch3 ICD), and Notch target gene Hey1 in PASMCs were upregulated. We further demonstrated that pharmacological inhibition of Notch3 activity by using a γ-secretase inhibitor DAPT, which blocked the cleavage of Notch proteins to ICD peptides, could effectively inhibit PASMC proliferation. Specifically knocked down of Notch3 in rat PASMCs by shRNA restored the abnormal PASMC phenotype in vitro. We found that administration of Notch signaling inhibitor DAPT could successfully reduce mean pulmonary arterial pressure in EUGR rats.

CONCLUSIONS

The present study demonstrated that upregulation of Notch3 signaling in PASMCs was crucial for the development of EUGR-induced PAH. Blocking Notch3-Hey1 signaling pathway in PASMCs provides a potential therapeutic target for PAH.

Dynamic proteomic changes in soft wheat seeds during accelerated ageing

Previous research demonstrated that soft wheat cultivars have better post-harvest storage tolerance than harder cultivars during accelerated ageing. To better understand this phenomenon, a tandem mass tag-based quantitative proteomic analysis of soft wheat seeds was performed at different storage times during accelerated ageing (germination ratios of 97%, 45%, 28%, and 6%). A total of 1,010 proteins were differentially regulated, of which 519 and 491 were up- and downregulated, respectively. Most of the differentially expressed proteins were predicted to be involved in nutrient reservoir, enzyme activity and regulation, energy and metabolism, and response to stimulus functions, consistent with processes occurring in hard wheat during artificial ageing. Notably, defense-associated proteins including wheatwin-2, pathogenesis-related proteins protecting against fungal invasion, and glutathione S-transferase and glutathione synthetase participating in reactive oxygen species (ROS) detoxification, were upregulated compared to levels in hard wheat during accelerated ageing. These upregulated proteins might be responsible for the superior post-harvest storage-tolerance of soft wheat cultivars during accelerated ageing compared with hard wheat. Although accelerated ageing could not fully mimic natural ageing, our findings provided novel dynamic proteomic insight into soft wheat seeds during seed deterioration.

S-nitrosylation of Src by NR2B-nNOS signal causes Src activation and NR2B tyrosine phosphorylation in levodopa-induced dyskinetic rat model

Abnormality in Src PSD-95 NR2B signaling complex assemble occurs in levodopa-induced dyskinesia (LID). N-methyl-D-aspartate receptor (NMDAR) subunit NR2B tyrosine phosphorylation mediated by Src family protein tyrosine kinases is closely associated with dyskinesia. Src autophosphorylation (p-Src) is an important part of Src-catalyzed phosphorylation of NR2B. In addition, the neuronal nitric oxide synthase (nNOS)-derived NO (nNOS/NO) signal which was also involved in dyskinesia recently was proved to participate in the regulation of Src function. Yet, the detailed signal mechanism about the interactions of NR2B, nNOS, and Src is still unknown. In the present study, we investigated the influences of nNOS on Src activation and NR2B tyrosine phosphorylation in dyskinetic rat model by immunoblotting and immunoprecipitation. The results demonstrated that chronic levodopa treatment resulted in downregulation of p-nNOS-S847, one marker of nNOS overactivation. Coinstantaneously, the S-nitrosylation (SNO-Src) and autophosphorylation (p-Src) of Src and NR2B tyrosine phosphorylation were upregulated in dyskinetic rat model. Conversely, administration of 7-NI, one nNOS inhibitor, reversed all these effects of levodopa treatment. Besides, NR2B-containing NMDAR (NR2B/NMDAR) antagonist CP-101,606 could upregulate p-nNOS-S847 and thus attenuate nNOS activation and simultaneously reduce the SNO-Src, p-Src, and NR2B tyrosine phosphorylation. Taken together, the S-nitrosylation of Src is caused by nNOS/NO signal, which is overactivated via Ca²⁺ influx dependent on NR2B/NMDAR, and subsequently facilitates Src auto-tyrosine phosphorylation and further phosphorylates NR2B. The "NR2B/NMDAR-nNOS/NO-SNO-Src-p-Src-NR2B/NMDAR" signaling cycle may be the molecular basis of NR2B tyrosine phosphorylation upward positive feedback, which demonstrates the possibility as one latent target for dyskinesia therapy.

[The attentional bias of emotion in medical workers of emergency department in one hospital and it's relationship with mood state]

Objective: To study the characteristics of attentional bias to emotional stimulus in medical workers of emergency department and explore the relationship between the emotional Stroop effect and mood states, thus providing a reference to the assessment and intervention of emergency medical workers' mental health. Methods: Two kinds of emotional Stroop tasks with words and pictures and the Profile of Mood States (POMS) were administered to thirty-six medical workers of emergency department and thirty-six medical workers of other departments. Results: The reaction time to negative and positive words and pictures were all higher than the reaction time to neutral stimulus, thus showing the significant Stroop effect in medical workers. The Stroop effect to negative emotional stimulus in medical workers of emergency department was significantly smaller than that in medical workers of other departments, while the difference of Stroop effect to positive stimulus was not significant between the two groups. Correlation analyses revealed that the correlations between Stroop effect size to positive pictures and tension and angry of POMS were all negatively significant (r value was -0.314 and -0.330 respectively) , and the correlation between Stroop effect size to negative pictures and fatigue was negatively significant (r=-0.303) . Conclusions: There is a significant emotional Stroop effect in medical workers. Although the ability of anti-interference to emotional stimulus in medical workers of emergency department was better than medical workers of the other departments, the long-term avoidance to negative emotional stimulus was still has a negative effect on the mood states of individuals.