RESUMO
The plasma membrane (PM) functions as a physical border between the extracellular and cytoplasmic environments that contribute to the interaction between host plants and pathogenic fungi. As a specific sterol constituent in the cell membrane, ergosterol plays a significant role in fungal development. However, the role of ergosterol in the infection of the rice blast fungus Magnaporthe oryzae remains unclear. In this study, we found that a sterol reductase, MoErg4, is involved in ergosterol biosynthesis and the regulation of plasma membrane integrity in M. oryzae. We found that defects in ergosterol biosynthesis disrupt lipid raft formation in the PM and cause an abnormal distribution of the t-soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein MoSso1, inhibiting its interaction with the v-SNARE protein MoSnc1. In addition, we found that MoSso1-MoSnc1 interaction is important for biotrophic interface complex development and cytoplasmic effector protein secretion. Our findings suggested that ergosterol-enriched lipid rafts constitute a platform for interactions among various SNARE proteins that are required for the development and pathogenicity of M. oryzae.
Assuntos
Ascomicetos , Magnaporthe , Oryza , Virulência , Proteínas Fúngicas/metabolismo , Ascomicetos/metabolismo , Proteínas SNARE/metabolismo , Oryza/metabolismo , Doenças das Plantas/microbiologiaRESUMO
Ferroptosis is a newly discovered form of cell death accompanied by iron accumulation and lipid peroxidation. Both biotic and abiotic stresses can induce ferroptosis in plant cells. In the case of plant interactions with pathogenic Phytophthora oomycetes, the roles of ferroptosis are still largely unknown. Here, we performed transcriptome analysis on soybean plants treated with the biocontrol agent Pythium oligandrum, a soilborne and non-pathogenic oomycete capable of inducing plant resistance against Phytophthora sojae infection. Expression of homologous soybean genes involved in ferroptosis and resistance was reprogrammed upon P. oligandrum treatment. Typical hallmarks for characterizing ferroptosis were detected in soybean hypocotyl cells, including decreased glutathione (GSH) level, accumulation of ferric ions, and lipid peroxidation by reactive oxygen species (ROS). Meanwhile, ferroptosis-like cell death was triggered by P. oligandrum to suppress P. sojae infection in soybean. Protection provided by P. oligandrum could be attenuated by the ferroptosis inhibitor ferrostatin-1 (Fer-1), suggesting the critical role of ferroptosis in soybean resistance against P. sojae. Taken together, these results demonstrate that ferroptosis is a P. oligandrum-inducible defence mechanism against oomycete infection in soybean.
Assuntos
Ferroptose , Phytophthora , Pythium , Glycine max/genética , Doenças das Plantas/prevenção & controle , Doenças das Plantas/genética , Resistência à Doença/genéticaRESUMO
Objective: To evaluate the detection ability of 18F-FDG PET/CT for identifying high-risk lesions (high-risk adenomas and adenocarcinoma) from incidental focal colorectal 18F-FDG uptake foci combining maximum standard uptake value (SUVmax) and localized colonic wall thickening (CWT). The secondary objective was to investigate the factors of missed detection of high-risk adenomas by 18F-FDG PET/CT. Patients and methods: A total of 6394 patients who underwent 18F-FDG PET/CT in our hospital from August 2019 to December 2021 were retrospectively analysed, and 145 patients with incidental focal colorectal 18F-FDG uptake foci were identified. The optimal cut-off value of SUVmax for 18F-FDG PET/CT diagnosis of high-risk lesions was determined by receiver operating characteristic (ROC) curves. SUVmax and localized CWT were combined to identify high-risk lesions from incidental focal colorectal 18F-FDG uptake foci. The characteristics of incidental adenomas detected and high-risk adenomas missed by 18F-FDG PET/CT were compared. Results: Of the 6394 patients, 145 patients were found to have incidental focal colorectal FDG uptake foci (2.3%), and 44 patients underwent colonoscopy and pathological examination at the same time. In fact, 45 lesions, including 12 low-risk lesions and 33 high-risk lesions (22 high-risk adenomas, 11 adenocarcinoma), were found by colonoscopy. The area under the ROC curve of SUVmax for low-risk lesions and high-risk lesions was 0.737, and the optimal cut-off value was 6.45 (with a sensitivity of 87.9% and specificity of 58.3%). When SUVmax ≥6.45, the combination of localized CWT parameters has little influence on the sensitivity and specificity of detection; when SUVmax <6.45, the combination of localized CWT parameters can improve the specificity of detection of high-risk lesions, but the sensitivity has little change. In addition, the size of high-risk adenomas discovered incidentally by 18F-FDG PET/CT was larger than that of high-risk adenomas missed, but there was no significant difference in lesion location, pathological type or intraepithelial neoplasia between the two groups. Conclusions: The combination of SUVmax and localized CWT parameters of 18F-FDG PET/CT helped identify high-risk lesions from incidental focal colorectal 18F-FDG uptake foci, especially for lesions with SUVmax <6.45. Lesion size may be the only factor in 18F-FDG PET/CT missing high-risk adenomas.
RESUMO
Cuticular proteins (CPs) play important roles in insect growth and development. However, it is unknown whether CPs are related to heat tolerance. Cnaphalocrocis medinalis, a serious pest of rice, occurs in summer and exhibits strong adaptability to high temperature, but the underlying mechanism is unclear. Here, the role of CP genes in heat acclimation was studied. Heat tolerance of the heat-acclimated larvae was significantly stronger than the unacclimated larvae. The cuticular protein content in the heat-acclimated larvae was higher than that of the unacclimated larvae. 191 presumed CP genes of C. medinalis (CmCPs) were identified. Expression patterns of 14 CmCPs were different between the heat acclimated (S39) and unacclimated (S27) larvae under heat stress. CmCPs were specifically expressed in epidermis and the head except CmCPR20 mainly expressed in Malpighian tubules. CmCPR20 was upregulated in S39 while downregulated in S27, but CmTweedle1 and CmCPG1 were upregulated in S27 and downregulated in S39. RNAi CmTweedle1 or CmCPG1 remarkably decreased heat tolerance and cuticular protein content of the heat-acclimated larvae but not the unacclimated larvae. RNAi CmCPR20 decreased heat tolerance and cuticular protein content of the unacclimated larvae but not the heat-acclimated larvae. CmTweedle1 and CmCPG1 genes involve heat acclimation of C. medinalis.
Assuntos
Aquecimento Global , Mariposas , Aclimatação , Animais , Insetos , Larva/genética , Mariposas/metabolismoRESUMO
Magnaporthe oryzae secretes several effectors that modulate and hijack rice processes to colonize host cells, but the underlying mechanisms remain unclear. We report on a novel cytoplasmic effector MoIug4 that targets the rice ethylene pathway as a transcription repressor to subvert host immunity. We found that MoIug4 binds to the promoter of the host OsEIN2 gene that encodes a central signal transducer in the ethylene-signaling pathway. We also identified a MoIug4 interacting protein, OsAHL1, which acts as an AT-hook motif-containing protein binding to the A/T-rich promoter regions. Our knockout and overexpression studies showed that OsAHL1 positively regulates plant immunity in response to M. oryzae infection. OsAHL1 exhibits transcriptional regulatory activities by binding the OsEIN2 promoter region, similar to MoIug4. Intriguingly, we found that MoIug4 exhibits a higher binding affinity than OsAHL1 to the OsEIN2 promoter, suggesting differential regulatory specificities. These results revealed a counter-defense strategy by which the pathogen effector suppresses the activation of host defense genes by interfering with host transcription activator functions.
Assuntos
Magnaporthe , Oryza , Etilenos/metabolismo , Interações Hospedeiro-Patógeno/genética , Magnaporthe/genética , Oryza/metabolismo , Doenças das Plantas/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcrição GênicaRESUMO
Disrupting the integrity of the sp2-carbon skeleton offers an effective strategy to create active sites for the oxygen reduction reaction (ORR). In this work, fullerene (C70) molecules, composed of 12 pentagons and 25 hexagons all bonded by sp2-C atoms, are assembled into microrods (C70MRs) at the liquid-liquid interface and then broken down by calcination to generate metal-free fullerene-derived ORR electrocatalysts. The effect of the pyrolysis temperature on C70MRs is investigated, and it is found that pyrolysis at 900 °C effectively unfolds the C70 cages and converts them into a highly porous, defect-rich carbon material (C70MRs-900) with the rod-shaped morphology well-retained. These structural features endow C70MRs-900 with outstanding ORR activity and stability together with remarkable methanol tolerance, better than C70MRs annealed at either lower (800 °C) or higher (1000 °C) temperatures. Furthermore, nitrogen atoms are successfully incorporated into the defective carbon skeleton by annealing C70MRs at 900 °C in the presence of NH4Cl. The resultant N-doped C70MRs-900 exhibits remarkable ORR performance with a half-wave potential of 0.836 V, comparable to that of the commercial 20% Pt/C catalyst. This work presents a simple and effective route of utilizing fullerene molecules as starting materials to develop high-performance metal-free, carbon-based electrocatalysts toward the ORR and even beyond.
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Electroencephalogram (EEG)-based quantitative pain measurement is valuable in the field of clinical pain treatment, providing objective pain intensity assessment especially for nonverbal patients who are unable to self-report. At present, a key challenge in modeling pain events from EEG is to find invariant representations for intra- and inter-subject variations, where current methods based on hand-crafted features cannot provide satisfactory results. Hence, we propose a novel method based on deep learning to learn such invariant representations from multi-channel EEG signals and demonstrate its great advantages in EEG-based pain classification tasks. To begin, instead of using typical EEG analysis techniques that ignore spatial information of EEG, we convert raw EEG signals into a sequence of multi-spectral topography maps (topology-preserving EEG images). Next, inspired by various deep learning techniques applied in neuroimaging domain, a deep Attentive-Recurrent-Convolutional Neural Network (ARCNN) is proposed here to learn spatial-spectral-temporal representations from EEG images. The proposed method aims to jointly preserve the spatial-spectral-temporal structures of EEG, for learning representations with high robustness against intra-subject and inter-subject variations, making it more conducive to multi-class and subject-independent scenarios. Empirical evaluation on 4-level pain intensity assessment within the subject-independent scenario demonstrated significant improvement over baseline and state-of-the-art methods in this field. Our approach applies deep neural networks (DNNs) to pain intensity assessment for the first time and demonstrates its potential advantages in modeling pain events from EEG.
Assuntos
Eletroencefalografia , Redes Neurais de Computação , Atenção , Eletroencefalografia/métodos , Humanos , Medição da DorRESUMO
The incidence of primary mixed adenoneuroendocrine carcinoma (MANEC) is rapidly increasing. MANEC mainly arises from the gastrointestinal tract, but occasionally it occurs as a pathological type of second primary malignancy (SPM). These SPMs can occur in the nasopharynx. Herein we describe the case of a first secondary nasopharyngeal MANEC that was detected 20 years after radical radiotherapy for nasopharyngeal carcinoma. The patient was a 50-year-old man who was admitted to our hospital after experiencing 1 month of left nasal congestion and ipsilateral tinnitus caused by a nasopharyngeal mass that was detected via physical examination and magnetic resonance imaging. A biopsy specimen from this nasopharyngeal lesion led to a histopathological diagnosis of recurrent nasopharyngeal carcinoma. He underwent high-dose palliative radiotherapy, followed by a course of gemcitabine-cisplatin-based adjuvant chemotherapy. These treatments failed to achieve local control of the tumor, and progressive left earache emerged. Another two forceps biopsies of the external auditory canal mass were conducted, and immunohistochemical testing for adenocarcinoma and neuroendocrine carcinoma markers including CK7, CK8, CK18, carcinoembryonic antigen, synaptophysin, chromogranin A, and CD56 was conducted. The diagnosis of MANEC was ultimately confirmed 5 months after the first visit, and one additional cycle of chemotherapy was subsequently performed. The patient died of hepatic metastases 8 months after the final diagnosis. Knowledge of this rare case will raise awareness of MANEC as a new pathological type of SPM originating in the nasopharynx, which will reduce delays and promote early diagnosis.
RESUMO
The production of reactive oxygen species (ROS) is a ubiquitous defense response in plants. Adapted pathogens evolved mechanisms to counteract the deleterious effects of host-derived ROS and promote infection. How plant pathogens regulate this elaborate response against ROS burst remains unclear. Using the rice blast fungus Magnaporthe oryzae, we uncovered a self-balancing circuit controlling response to ROS in planta and virulence. During infection, ROS induces phosphorylation of the high osmolarity glycerol pathway kinase MoOsm1 and its nuclear translocation. There, MoOsm1 phosphorylates transcription factor MoAtf1 and dissociates MoAtf1-MoTup1 complex. This releases MoTup1-mediated transcriptional repression on oxidoreduction-pathway genes and activates the transcription of MoPtp1/2 protein phosphatases. In turn, MoPtp1/2 dephosphorylate MoOsm1, restoring the circuit to its initial state. Balanced interactions among proteins centered on MoOsm1 provide a means to counter host-derived ROS. Our findings thereby reveal new insights into how M. oryzae utilizes a phosphor-regulatory circuitry to face plant immunity during infection.
Assuntos
Ascomicetos/enzimologia , Proteínas Fúngicas/metabolismo , Regulação Enzimológica da Expressão Gênica/fisiologia , Regulação Fúngica da Expressão Gênica/fisiologia , Oryza/microbiologia , Espécies Reativas de Oxigênio , Adaptação Fisiológica , Ascomicetos/genética , Proteínas Fúngicas/genética , Oryza/metabolismo , Oxirredução , Estresse Oxidativo/fisiologia , Fosforilação , Doenças das Plantas/microbiologiaRESUMO
AIM: To evaluate the effectiveness and safety of percutaneous hepatic cryoablation in combination with percutaneous ethanol injection (PEI) in patients with unresectable hepatocellular carcinoma (HCC). METHODS: A total of 105 masses in 65 HCC patients underwent percutaneous hepatic cryoablation. The cryoablation was performed with the Cryocare system (Endocare, Irvine, CA, USA) using argon gas as a cryogen. Two freeze-thaw cycles were performed, each reaching a temperature of -180 degrees C at the tip of the probe. PEI was given in 36 patients with tumor masses larger than 6 cm in diameter 1-2 weeks after cryoablation and then once per week for 4 to 6 sessions. The efficacy was evaluated with survival, change of tumor size and alpha-fetoprotein (AFP) levels. RESULTS: During a follow-up duration of 14 months in average with a range of 5 to 21 months, 33 patients (50.8%) were free of tumors, 22 patients (33.8%) alive with tumor recurrence: two had bone metastases, three were found to have lung metastases, and the remaining 17 recurrences occurred in the liver, of whom only 3 developed a cryosite recurrence. Among the 41 patients who were followed up for more than one year, 32(78%) were alive despite of tumor recurrence. Seven patients (10.8%) died due to disease recurrence. Three patients (4.6%) died due to some noncancer-related causes. Among the 43 patients who had a CT scan available for review, 38 (88.4%) had a shrinkage of tumor mass. Among the 22 patients who received biopsies of cryoablated tumor mass, all biopsies except one, showed only dead or scar tissues. Of the patients who had an increased AFP preablatively, 91.3% had a decrease of AFP to normal or nearly normal levels during postablative 3-6 months. Complications of cryoablation included liver capsular cracking in one patient,transient thrombocytopenia in 4 patients and asymptomatic right-sided pleural effusions in 2 patients. Two patients developed liver abscess at the previous cryoablation site at 2 and 4 months, respectively, following cryoablation, and was recovered after treated with antibiotics and drainage. CONCLUSION: Percutaneous cryoablation offers a safe and possibly curative treatment option for patients with HCC that cannot be surgically removed, and its integration with PEI, may serve as an alternative to partial liver resection in selective patients.
Assuntos
Carcinoma Hepatocelular/terapia , Criocirurgia , Etanol/uso terapêutico , Neoplasias Hepáticas/terapia , Administração Cutânea , Adulto , Idoso , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/cirurgia , Terapia Combinada , Etanol/administração & dosagem , Feminino , Humanos , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/cirurgia , Masculino , Pessoa de Meia-Idade , Análise de Sobrevida , Fatores de Tempo , Resultado do TratamentoRESUMO
OBJECTIVES: To determine the expression of nitric oxide synthase (NOS) in testis and to investigate the effects of NO on the reproductive function of testis. METHODS: Testes of adult male Sprague-Dawley rats were fixed in 4% paraformaldehyde. The paraffin sections were made as routine. Immunohistochemical ABC method was used to observe the localization of NOS. RESULTS: Endothelia NOS (eNOS), neuronal NOS (nNOS) and inductive NOS (iNOS) were all expressed in Leydig cells. Only eNOS was expressed in peritubular myoid cells, endothelial and smooth muscle cells of blood vessel, while only nNOS expressed in tunica adventitia of testicular blood vessels. The reactive substance distributes in cytoplasm with negative nuclei. Immunoreactivity for eNOS, nNOS and iNOS in all spermatogenic cells was negative. CONCLUSIONS: Three kinds of NOS were all expressed in testis and the distribution of different NOS had a little difference.