RESUMO
BACKGROUND: Water content and chlorophyll content are important indicators for monitoring rice growth status. Simultaneous detection of water content and chlorophyll content is of significance. Different varieties of rice show differences in phenotype, resulting in the difficulties of establishing a universal model. In this study, hyperspectral imaging was used to detect the Soil and Plant Analyzer Development (SPAD) values and water content of fresh rice leaves of three rice varieties (Jiahua 1, Xiushui 121 and Xiushui 134). RESULTS: Both partial least squares regression and convolutional neural networks were used to establish single-task and multi-task models. Transfer component analysis (TCA) was used as transfer learning to learn the common features to achieve an approximate identical distribution between any two varieties. Single-task and multi-task models were also built using the features of the source domain, and these models were applied to the target domain. These results indicated that for models of each rice variety the prediction accuracy of most multi-task models was close to that of single-task models. As for TCA, the results showed that the single-task model achieved good performance for all transfer learning tasks. CONCLUSION: Compared with the original model, good and differentiated results were obtained for the models using features learned by TCA for both the source domain and target domain. The multi-task models could be constructed to predict SPAD values and water content simultaneously and then transferred to another rice variety, which could improve the efficiency of model construction and realize rapid detection of rice growth indicators. © 2024 Society of Chemical Industry.
RESUMO
This study aimed to reveal the diversity and variation in panicle traits of the Chinese prickly ash and clarify their influence on the its systematic classification to provide a theoretical basis and technical support for the efficient utilization of Chinese prickly ash germplasm resources and breeding. Sixteen panicle traits were identified from 35 Chinese prickly ash germplasm resources from 2021 to 2022. The diversity of these panicle traits and their role in the plant's systematic classification were studied using variance, correlation, cluster, and principal component analyses. Cluster analysis showed that the 35 Chinese prickly ash germplasm resources could be divided into two groups with Euclidean distances of 25. Further analysis showed that yield traits such as panicle length, panicle width, primary branching, grain number per panicle, and grain weight per panicle were significantly positively correlated with grain chlorophyll content, while grain anthocyanin content was negatively correlated with both panicle (panicle length, panicle width, panicle length to width ratio, primary branching, grain number per panicle, and grain weight per panicle) and grain characteristics (single grain weight, thousand-grain weight, grain length, grain width and fruit shape index). In conclusion, Chinese prickly ash germplasms have diverse panicle traits. Z. armatum has dark green grains, long and wide panicles, a long conical shape, many primary branches, high grain weight, and high grain number per panicle. In contrast, Z. bungeanum has bright red seeds, a panicle width larger than its length, short and conical panicles, a small number of primary branches, and low grain weight per panicle and number of grains per panicle. Overall, Z. armatum had a significant yield advantage over Z. bungeanum.
Assuntos
Rutaceae , Sementes , China , Clorofila/análise , Análise por Conglomerados , Variação Genética , Fenótipo , Melhoramento Vegetal , Análise de Componente Principal , Característica Quantitativa Herdável , Sementes/crescimento & desenvolvimento , Sementes/anatomia & histologia , Rutaceae/classificaçãoRESUMO
Rapeseed (Brassica napus L.) seedlings suffering from inappropriate growth substrate stress will present poor seedling quality. However, the regulatory mechanism for the production and scavenging of reactive oxygen species (ROS) caused by this type of stress remains unclear. In the current study, a split plot experiment design was implemented with two crop growth substrates-a rice growth substrate (RIS) and rapeseed growth substrate (RAS)-as the main plot and two genotypes-a hybrid and an open-pollinated variety (Zheyouza 1510 and Zheyou 51, respectively)-as the sub-plot. The seedling quality was assessed, and the ROS production/scavenging capacity was evaluated. Enzymatic and non-enzymatic systems, including ascorbic acid and glutathione metabolism, and RNA-seq data were analyzed under the two growth substrate treatments. The results revealed that rapeseed seedling quality decreased under RIS, with the plant height, maximum leaf length and width, and aboveground dry matter being reduced by 187.7%, 64.6%, 73.2%, and 63.8% on average, respectively, as compared to RAS. The main type of ROS accumulated in rapeseed plants was hydrogen peroxide, which was 47.8% and 14.1% higher under RIS than under RAS in the two genotypes, respectively. The scavenging of hydrogen peroxide in Zheyouza 1510 was the result of a combination of enzymatic systems, with significantly higher peroxidase (POD) and catalase (CAT) activity as well as glutathione metabolism, with significantly higher reduced glutathione (GSH) content, under RAS, while higher oxidized glutathione (GSSH) was observed under RIS. However, the scavenging of hydrogen peroxide in Zheyou 51 was the result of a combination of elevated oxidized ascorbic acid (DHA) under RIS and higher GSH content under RAS. The identified gene expression levels were in accordance with the observed enzyme expression levels. The results suggest that the cost of substituting RAS with RIS is a reduction in rapeseed seedling quality contributing to excessive ROS production and a reduction in ROS scavenging capacity.
RESUMO
A visible-light-induced radical-radical cross-coupling reaction between 1,3,4-oxadiazoles and hydroxamic acid derivatives has been realized under base- and metal-free conditions. The protocol was characterized by broad substrate scope, excellent functional group tolerance, and simple operation procedures. By using this protocol, a variety of biologically important 5-aryl-1,3,4-oxadiazole-2-methylamines were obtained in good yields with excellent chemoselectivity.
RESUMO
Sepsis is a systemic inflammatory reaction caused by infection, and severe sepsis can develop into septic shock, eventually leading to multiorgan dysfunction and even death. In recent years, studies have shown that mitochondrial damage is closely related to the occurrence and development of sepsis. Recent years have seen a surge in concern over mitochondrial DNA (mtDNA), as anomalies in this material can lead to cellular dysfunction, disruption of aerobic respiration, and even death of the cell. In this review, we discuss the latest findings on the mechanisms of mitochondrial damage and the molecular mechanisms controlling mitochondrial mtDNA release. We also explored the connection between mtDNA misplacement and inflammatory activation. Additionally, we propose potential therapeutic targets of mtDNA for sepsis treatment.
RESUMO
Ogura cytoplasmic male sterility (CMS) is considered the rapeseed (Brassica napus L.) with the most potential to be utilized as a heterosis system worldwide, but it lacks sufficient restorers. In this study, root tip cell (RTC) mitotic and pollen mother cell (PMC) meiosis observations were compared to ensure the number of chromosomes and the formation of a chromosomal bridge using restorer lines R2000, CLR650, and Zhehuhong (a new restorer) as the experimental material. Further, molecular markers of exogenous chromosomal fragments were detected and the sequence and expression differences of restorer genes in the three lines were determined to identify the distinctive characteristics of Zhehuhong. The results showed that the number of chromosomes in Zhehuhong was stable (2n = 38), indicating that the exogenous radish chromosome segment had been integrated into the chromosome of Zhehuhong. Molecular marker detection revealed that Zhehuhong was detected at most loci, with only the RMA05 locus being missed. The exogenous radish chromosome segment of Zhehuhong differed from R2000 and CLR650. The pollen mother cells of Zhehuhong showed chromosome lagging in the meiotic metaphase I, meiotic anaphase I, and meiotic anaphase II, which was consistent with R2000 and CLR650. The restorer gene PPRB in Zhehuhong had 85 SNPs compared with R2000 and 119 SNPs compared with CLR650, indicating the distinctive characteristic of PPRB in Zhehuhong. In terms of the spatial expression of PPRB, the highest level was detected in the anthers in the three restorer lines. In addition, in terms of temporal expression, the PPRB gene expression of Zhehuhong was highest at a bud length of 4 mm. Our results clearly indicated that Zhehuhong is a new restorer line for the Ogura CMS system, which can be used further in rapeseed heterosis utilization.
RESUMO
Background: The IQ motif and Sec7 domain ArfGEF 2 (IQSEC2), an X-linked gene that encodes the BRAG1 protein, is a guanine nucleotide exchange factor for the ADP ribosylation factor (ARF) protein family in the small guanosine triphosphate (GTP) binding protein. Mutations in this gene result in disorders such as intellectual disability (ID) and epilepsy. In this study, we analyze the clinical features of two patients with IQSEC2-mutation-related disease and discuss their possible pathogenesis. Methods: The two patients were diagnosed with ID and epilepsy. Genetic testing was performed using whole-exome sequencing, and the three-dimensional protein structure was analyzed. UCSC Genome Browser was used to analyze the conservation of IQSEC2 in different species. We compared IQSEC2 expression in the proband families with that in a control group, as well as the expression of the postsynaptic identity protein 95 (PSD-95), synapse-associated protein 97 (SAP97), ADP ribosylation factor 6 (ARF-6), and insulin receptor substrate 53kDa (IRSP53) genes interacting with IQSEC2. Results: We identified two semi-zygote mutations located in conserved positions in different species: an unreported de novo mutation, C.3576C>A (p. Tyr1192*), and a known mutation, c.2983C>T (p. Arg995Trp). IQSEC2 mutations resulted in significant changes in the predicted three-dimensional protein structure, while its expression in the two probands was significantly lower than that in the age-matched control group, and IQSEC2 expression in proband 1 was lower than that in his family members. The expression levels of PSD-95, ARF-6, and SAP97, IRSP 53, which interact with IQSEC2, were also significantly different from those in the family members and age-matched healthy children. Conclusion: The clinical phenotype resulting from IQSEC2 mutations can be explained by the significant decrease in its expression, loss of function of the mutant protein, and change in the expression of related genes. Our results provide novel insights into the molecular phenotype conferred by the IQSEC2 variants.
RESUMO
Phage therapy offers a promising approach to combat the growing threat of antimicrobial resistance. Yet, key questions remain regarding dosage, administration routes, combination therapy, and the causes of therapeutic failure. In this study, we focused on a novel lytic phage, ФAb4B, which specifically targeted the Acinetobacter baumannii strains with KL160 capsular polysaccharide, including the pan-drug resistant A. baumannii YQ4. ФAb4B exhibited the ability to effectively inhibit biofilm formation and eradicate mature biofilms independently of dosage. Additionally, it demonstrated a wide spectrum of antibiotic-phage synergy and did not show any cytotoxic or haemolytic effects. Continuous phage injections, both intraperitoneally and intravenously over 7 d, showed no acute toxicity in vivo. Importantly, phage therapy significantly improved neutrophil counts, outperforming ciprofloxacin. However, excessive phage injections suppressed neutrophil levels. The combinatorial treatment of phage-ciprofloxacin rescued 91% of the mice, a superior outcome compared to phage alone (67%). The efficacy of the combinatorial treatment was independent of phage dosage. Notably, prophylactic administration of the combinatorial regimen provided no protection, but even when combined with a delayed therapeutic regimen, it saved all the mice. Bacterial resistance to the phage was not a contributing factor to treatment failure. Our preclinical study systematically describes the lytic phage's effectiveness in both in vitro and in vivo settings, filling in crucial details about phage treatment against bacteriemia caused by A. baumannii, which will provide a robust foundation for the future of phage therapy.
Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , Antibacterianos , Bacteriófagos , Biofilmes , Ciprofloxacina , Farmacorresistência Bacteriana Múltipla , Terapia por Fagos , Acinetobacter baumannii/virologia , Acinetobacter baumannii/efeitos dos fármacos , Terapia por Fagos/métodos , Infecções por Acinetobacter/terapia , Infecções por Acinetobacter/microbiologia , Animais , Biofilmes/efeitos dos fármacos , Bacteriófagos/fisiologia , Camundongos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Ciprofloxacina/uso terapêutico , Ciprofloxacina/farmacologia , Modelos Animais de Doenças , Feminino , Camundongos Endogâmicos BALB CRESUMO
BACKGROUND: Metabolic disorders (MetDs) have been demonstrated to be closely linked to numerous diseases. However, the precise association between MetDs and pulmonary tuberculosis (PTB) remains poorly understood. METHOD: Summary statistics for exposure and outcomes from genome-wide association studies (GWASs) for exposures and outcomes were obtained from the BioBank Japan Project (BBJ) Gene-exposure dataset. The 14 clinical factors were categorized into three groups: metabolic laboratory markers, blood pressure, and the MetS diagnostic factors. The causal relationship between metabolic factors and PTB were analyzed using two-sample Mendelian Randomization (MR). Additionally, the direct effects on the risk of PTB were investigated through multivariable MR. The primary method employed was the inverse variance-weighted (IVW) model. The sensitivity of this MR analysis was evaluated using MR-Egger regression and the MR-PRESSO global test. RESULTS: According to the two-sample MR, HDL-C, HbA1c, TP, and DM were positively correlated with the incidence of active TB. According to the multivariable MR, HDL-C (IVW: OR 2.798, 95% CI 1.484-5.274, P = 0.001), LDL (IVW: OR 4.027, 95% CI 1.140-14.219, P = 0.03) and TG (IVW: OR 2.548, 95% CI 1.269-5.115, P = 0.009) were positively correlated with the occurrence of PTB. TC (OR 0.131, 95% CI 0.028-0.607, P = 0.009) was negatively correlated with the occurrence of PTB. We selected BMI, DM, HDL-C, SBP, and TG as the diagnostic factors for metabolic syndrome. DM (IVW, OR 1.219, 95% CI 1.040-1.429 P = 0.014) and HDL-C (IVW, OR 1.380, 95% CI 1.035-1.841, P = 0.028) were directly correlated with the occurrence of PTB. CONCLUSIONS: This MR study demonstrated that metabolic disorders, mainly hyperglycemia, and dyslipidemia, are associated with the incidence of active pulmonary tuberculosis.
Assuntos
Estudo de Associação Genômica Ampla , Análise da Randomização Mendeliana , Doenças Metabólicas , Tuberculose Pulmonar , Humanos , Tuberculose Pulmonar/genética , Tuberculose Pulmonar/epidemiologia , Tuberculose Pulmonar/sangue , Doenças Metabólicas/genética , Doenças Metabólicas/epidemiologia , Fatores de RiscoRESUMO
The rise of antimicrobial resistance in ESKAPEE pathogens poses significant clinical challenges, especially in polymicrobial infections. Bacteriophage-derived endolysins offer promise in combating this crisis, but face practical hurdles. Our study focuses on engineering endolysins from a Klebsiella pneumoniae phage, fusing them with ApoE23 and COG133 peptides. We assessed the resulting chimeric proteins' bactericidal activity against ESKAPEE pathogens in vitro. ApoE23-Kp84B (CHU-1) reduced over 3 log units of CFU for A. baumannii, E. faecalis, K. pneumoniae within 1 h, while COG133-Kp84B (CHU-2) showed significant efficacy against S. aureus. COG133-L1-Kp84B, with a GS linker insertion in CHU-2, exhibited outstanding bactericidal activity against E. cloacae and P. aeruginosa. Scanning electron microscopy revealed alterations in bacterial morphology after treatment with engineered endolysins. Notably, CHU-1 demonstrated promising anti-biofilm and anti-persister cell activity against A. baumannii and E. faecalis but had limited efficacy in a bacteremia mouse model of their coinfection. Our findings advance the field of endolysin engineering, facilitating the customization of these proteins to target specific bacterial pathogens. This approach holds promise for the development of personalized therapies tailored to combat ESKAPEE infections effectively.
RESUMO
Aspergillus westerdijkiae can infect many agricultural products including cereals, grapes, and pear. Pathogenic fungi secrete diverse effectors as invasive weapons for successful invasion the host plant. During the pathogen-host interaction, 4486 differentially expressed genes were observed in A. westerdijkiae with 2773 up-regulated and 1713 down-regulated, whereas 8456 differentially expressed genes were detected in pear fruits with 4777 up-regulated and 3679 down-regulated. A total of 309 effector candidate genes were identified from the up-regulated genes in A. westerdijkiae. Endoglucanase H (AwEGH) was significantly induced during the pathogen-host interaction. Deletion of AwEGH resulted in altered fungal growth and morphology and reduced conidia production and germination compared to the wild-type. Further experiments demonstrated that AwEGH plays a role in cell wall integrity. Importantly, disruption of AwEGH significantly reduced the fungal virulence on pear fruits, and this defect can be partly explained by the impaired ability of A. westerdijkiae to penetrate host plants.
Assuntos
Aspergillus , Celulase , Pyrus , Pyrus/genética , Celulase/genética , Virulência , Frutas/genética , Proteínas Fúngicas/genéticaRESUMO
In this study, we prepared high-nitrogen self-doped porous carbons (NPC1 and NPC2) derived from the pruned branches and seeds of Zanthoxylum bungeanum using a simple one-step method. NPC1 and NPC2 exhibited elevated nitrogen contents of 3.56% and 4.22%, respectively, along with rich porous structures, high specific surface areas of 1492.9 and 1712.7 m2 g-1 and abundant surface groups. Notably, both NPC1 and NPC2 demonstrated remarkable adsorption abilities for the pollutant methylene blue (MB), with maximum monolayer adsorption capacities of 568.18 and 581.40 mg g-1, respectively. The adsorption kinetics followed the pseudo-second-order kinetics and the adsorption isotherms conformed to the Langmuir isotherm model. The adsorption mechanism primarily relied on the hierarchical pore structures of NPC1 and NPC2 and their diverse strong interactions with MB molecules. This study offers a new approach for the cost-effective design of nitrogen self-doped porous carbons, facilitating the efficient removal of MB from wastewater.
Assuntos
Carbono , Azul de Metileno , Nitrogênio , Zanthoxylum , Zanthoxylum/química , Adsorção , Nitrogênio/química , Azul de Metileno/química , Porosidade , Carbono/química , Cinética , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Águas Residuárias/químicaRESUMO
Background: Identifying the fundus objective biomarkers for the major depressive disorders (MDD) may help promote mental health. The aim of this study was to evaluate retinal neurovascular changes and further investigate their association with disease severity in MDD. Methods: This cross-sectional study conducted in the hospital enrolled patients with MDD and healthy controls.The retinal neurovascular parameters for all subjects, including vessel density (VD), thickness of ganglion cell complex (GCC) and retinal nerve fiber layer (RNFL), and optic nerve head (ONH) eg are automatically calculated by the software in optical coherence tomography angiography (OCTA). The severity of MDD including depressive symptoms, anxiety, cognition, and insomnia was assessed by Hamilton Depression Rating Scale (HAMD), Hamilton Anxiety Scale (HAMA), Montreal Cognitive Assessment (MoCA), and Insomnia Severity Index (ISI) respectively. Results: This study included 74 MDD patients (n=74 eyes) and 60 healthy controls (HCs) (n=60 eyes). MDD patients showed significantly decreased VD of superficial and deep capillary plexus, thickness of GCC and RNFL, and volume of ONH (all p<0.05) and increased vertical cup-to-disc ratio and global loss volume (GLV) (all p<0.05) compared to HCs. Positive associations were found between HAMD scores and cup area (r=0.30, p=0.035), cup volume (r=0.31, p=0.029), and disc area (r=0.33, p=0.020) as well as ISI scores and RNFL thickness (r=0.34, p=0.047). Conclusion: We found the retinal neurovascular impairment and its association with disease severity in MDD patients. OCTA showed promise as a potential complementary assessment tool for MDD.
RESUMO
Microplastic pollution is a pressing global environmental concern with particular urgency surrounding the issue of nanoplastic particles. Plastic products exhibit a remarkable persistence in natural ecosystems, resisting easy degradation. Nanoplastics, characterized by their diminutive size, possess distinct properties when compared to their larger counterparts, which could potentially render them more ecologically detrimental. Microplastics themselves serve as carriers for toxic and hazardous substances, such as plastic additives, that enter and persist in the environmental cycle. Importantly, nanoplastics exhibit enhanced bioavailability upon entering the food chain. Notably, studies have demonstrated the adverse effects of nanoplastics on the reproductive function of aquatic organisms, and evidence of micro- and nanoplastics have emerged within human reproductive organs, including the placenta. However, a knowledge gap persists regarding the impacts of nanoplastics on the reproductive systems of mammals and, indeed, humans. This paper aims to elucidate the less frequently discussed sources and distribution of nanoplastics in the environment, along with the pathways of human exposure. We also emphasize the extent to which nanoplastics accumulate within the reproductive systems of organisms. Subsequently, we present an in-depth analysis of the effects of nanoplastics and their associated contaminants on mammalian and human reproductive health. The mechanisms through which nanoplastics contribute to reproductive disorders are comprehensively explored, highlighting their potential to disrupt endocrine levels in mammals and humans. Additionally, we scrutinize and discuss studies on biotoxicity of nanoplastics, offering insights into potential areas for future research.
Assuntos
Microplásticos , Saúde Reprodutiva , Humanos , Animais , Microplásticos/toxicidade , Exposição Ambiental/efeitos adversos , Feminino , Reprodução/efeitos dos fármacos , Nanopartículas/toxicidade , Poluentes Químicos da Água/toxicidade , GravidezRESUMO
The morphological, physiological, and biochemical characteristics of leaves result from the long-term adaptation of plants to their environment and are closely related to plant growth and development. In this study, 37 prickly ash germplasm resources from 18 production areas were utilized as the subjects of research. Logistic equations, principal component analysis, and cluster analysis were employed to comprehensively evaluate the leaf traits of prickly ash germplasm resources, with an analysis of their correlation with ecological and geographical factors in the production areas. The results showed that the leaf traits of prickly ash germplasms of different origins are substantially different and diverse. The coefficient of variation for the 14 leaf traits was greater than 10%. The coefficient of variation of the compound leaflet number was the highest among all the considered leaf traits, and the coefficient of variation of leaf thickness was the lowest, at 49.86% and 11.37%, respectively. The leaf traits of the prickly ash germplasm originating from Chongqing in Yongchuan, Chongqing in Rongchang, and Yunnan in Honghe ranked highest, whereas the leaf traits of the prickly ash germplasm from Henan in Jiaozuo, Gansu in Tianshui, and Shanxi in Yuncheng ranked lowest. The results of the correlation analysis showed that among the ecological and geographical factors of the origins, latitude had the strongest correlation with the leaf traits of the prickly ash germplasm. As latitude increased, the leaves of prickly ash gradually decreased in size, weight, and leaf shape index. The factor with the second strongest correlation was temperature. The leaves of the prickly ash germplasm originating from warmer climate areas were larger and heavier than those from areas with colder climates. Altitude and longitude did not significantly affect the leaf traits of the prickly ash germplasm, but at similar latitudes, the leaves of the prickly ash germplasm in high-altitude areas were smaller, and the leaves of the prickly ash germplasm in low-altitude areas were larger. These findings can provide valuable references for breeding and the sustainable utilization of new varieties of prickly ash resources.
Assuntos
Altitude , Melhoramento Vegetal , Humanos , China , Geografia , Folhas de PlantaRESUMO
The objective of this study was to investigate the potential targets and mechanism of Rheum palmatum L in the treatment of colorectal cancer based on the network pharmacology and molecular docking, which could provide the theoretical basis for clinical applications. The potential components were screened using TCMSP database and articles. The gene targets of colorectal cancer were screened through the Genecards database and Online Mendelian Inheritance in Man database. Then, the common targets of components and colorectal cancer were used to construct the network diagram of active components and targets in Cytoscape 3.7.0. The protein-protein interaction (PPI) diagram was generated using String database, and the targets were further analyzed by gene ontology and Kyoto Encyclopedia of Genes and Genomes. Molecular docking between gene targets and active components was analyzed via AutoDock, and visualized through PyMol. Among this study, main targets might be TP53, EGF, MYC, CASP3, JUN, PTGS2, HSP90AA1, MMP9, ESR1, PPARG. And 10 key elements might associate with them, such as aloe-emodin, beta-sitosterol, gallic acid, eupatin, emodin, physcion, cis-resveratrol, rhein, crysophanol, catechin. The treatment process was found to involve nitrogen metabolism, p53 signaling pathway, and various cancer related pathway, as well as the AGE-RAGE signaling pathway, estrogen signaling pathway, interleukin-17 signaling pathway and thyroid hormone signaling pathway. The molecular docking was verified the combination between key components and their respective target proteins. Network pharmacological analysis demonstrated that R palmatum was could regulated p53, AGE-RAGE, interleukin-17 and related signaling pathway in colorectal cancer, which might provide a scientific basis of mechanism.
Assuntos
Neoplasias Colorretais , Medicamentos de Ervas Chinesas , Emodina , Rheum , Humanos , Simulação de Acoplamento Molecular , Interleucina-17 , Proteína Supressora de Tumor p53 , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/uso terapêuticoRESUMO
Antimicrobial peptides (AMPs) hold promise as alternatives to combat bacterial infections, addressing the urgent global threat of antibiotic resistance. COG1410, a synthetic peptide derived from apolipoprotein E, has exhibited potent antimicrobial properties against various bacterial strains, including Mycobacterium smegmatis. However, our study reveals a previously unknown resistance mechanism developed by M. smegmatis against COG1410 involving ClpC. Upon subjecting M. smegmatis to serial passages in the presence of sub-MIC COG1410, resistance emerged. The comparative genomic analysis identified a point mutation in ClpC (S437P), situated within its middle domain, which led to high resistance to COG1410 without compromising bacterial fitness. Complementation of ClpC in mutant restored bacterial sensitivity. In-depth analyses, including transcriptomic profiling and in vitro assays, uncovered that COG1410 interferes with ClpC at both transcriptional and functional levels. COG1410 not only stimulated the ATPase activity of ClpC but also enhanced the proteolytic activity of Clp protease. SPR analysis confirmed that COG1410 directly binds with ClpC. Surprisingly, the identified S437P mutation did not impact their binding affinity. This study sheds light on a unique resistance mechanism against AMPs in mycobacteria, highlighting the pivotal role of ClpC in this process. Unraveling the interplay between COG1410 and ClpC enriches our understanding of AMP-bacterial interactions, offering potential insights for developing innovative strategies to combat antibiotic resistance.
RESUMO
The discovery of ferrocene in 1951 was a significant landmark in the field of organometallic chemistry, and since then, numerous sandwich- or half-sandwich metallic complexes have been reported. However, silver stands as an intriguing exception in this regard, and knowledge of its bonding situation has remained undisclosed. Herein, unprecedented 12-vertex metallacarboranes of Ag(I) (2a and 2b) were synthesized through the reaction of sodium hexamethyldisilazide (NaHMDS) with the mixture of nido-C2B9 carborane anion-supported N-heterocyclic carbene precursors (1a and 1b) and [Ag(PPh3)Cl]4. The X-ray structural analysis of the resulting metallacarboranes revealed a unique "slipped" half-sandwich structure, which is a rarity among cyclopentadienyl analogues. DFT calculations provided insights into the asymmetric π-interactions between the pentagonal C2B3 face and the silver ion.
RESUMO
The fungus Coleosporium zanthoxyli causes leaf rust in Chinese pepper (Zanthoxylum armatum). To investigate the control effect of elicitor treatment on leaf rust in this species, the impact of salicylic acid (SA) on the spores and growth of C. zanthoxyli and the induced resistance to leaf rust by Z. armatum were analyzed, and the possible defense mechanisms involved in SA induction were evaluated. The results showed that SA had no effect on C. zanthoxyli spore germination and growth; however, rust resistance was induced in Z. armatum. The optimal SA treatment concentration was 0.4 mg/ml, and the relative cure effect reached 44.56%. SA-induced disease resistance was evident for up to 10 days, while the optimal induction interval was 48 h after stimulation. Consistent with the induced resistance, H2O2, total protein, total phenol, and lignin concentrations and polyphenol oxidase (PPO), peroxidase (POD), phenylalanine ammonia lyase (PAL), superoxide dismutase (SOD), and catalase (CAT) activities were significantly increased with the SA treatment, whereas the malondialdehyde content was significantly decreased. In addition, exogenous SA promoted defense-related enzyme activities, including those of POD, CAT, and PAL, and increased H2O2, lignin, and endogenous SA contents. Furthermore, SA induced the expression of SA signaling pathway genes such as ZaPR1 and ZaNPR1, and silencing ZaPR1 enhanced the sensitivity of Z. armatum to leaf rust. Our results demonstrated that 0.4 mg/ml SA priming increased the activities of CAT, POD, and PAL, elevated the contents of H2O2, lignin, and endogenous SA, and upregulated the expression of the SA-related gene ZaPR1, thereby enhancing the resistance of Z. armatum to leaf rust.
RESUMO
BACKGROUND: Microcirculatory dysfunction is associated with increased morbidity and mortality in cardiac surgery patients. This study aimed to investigate the association between preoperative retinal microcirculation evaluated using optical coherence tomography angiography (OCTA) and perioperative outcomes in patients with congenital heart disease (CHD). METHODS: This prospective, observational study was performed from May 2017 to January 2021. OCTA was used to automatically quantify the vessel density (VD) of the superficial capillary plexus, deep capillary plexus (DCP), and radial peripapillary capillary (RPC) preoperatively. The primary outcome was excessive postoperative bleeding, defined as bleeding volume > 75th percentile for 24-hour postoperative chest tube output. The secondary outcome was composite adverse outcomes, including one or more operative mortalities, early postoperative complications, and prolonged length of stay. The association between retinal VD and outcomes was assessed using Poisson regression. RESULTS: In total, 173 CHD patients who underwent cardiac surgery were included (mean age, 26 years). Among them, 43 (24.9%) and 46 (26.6%) developed excessive postoperative bleeding and composite adverse outcomes, respectively. A lower VD of DCP (odds ratio [OR], 1.24; 95% confidence interval [CI], 1.08-1.43; P = 0.003) was independently associated with excessive postoperative bleeding, and a lower VD of RPC (OR, 1.97; 95% CI, 1.08-3.57; P = 0.027), and DCP (OR, 2.17; 95% CI, 1.08-4.37; P = 0.029) were independently associated with the postoperative composite adverse outcomes. CONCLUSION: Preoperative retinal hypoperfusion was independently associated with an increased risk of perioperative adverse outcomes in patients with CHD, suggesting that retinal microcirculation evaluation could provide valuable information about the outcomes of cardiac surgery, thereby aiding physicians in tailoring individualized treatment.