RESUMEN
The emergence of phytopathogenic bacteria resistant to antibacterial agents has rendered previously manageable plant diseases intractable, highlighting the need for safe and environmentally responsible agrochemicals. Inhibition of bacterial cell division by targeting bacterial cell division protein FtsZ has been proposed as a promising strategy for developing novel antibacterial agents. We previously identified 4'-demethylepipodophyllotoxin (DMEP), a naturally occurring substance isolated from the barberry species Dysosma versipellis, as a novel chemical scaffold for the development of inhibitors of FtsZ from the rice blight pathogen Xanthomonas oryzae pv. oryzae (Xoo). Therefore, constructing structure-activity relationship (SAR) studies of DMEP is indispensable for new agrochemical discovery. In this study, we performed a structure-activity relationship (SAR) study of DMEP derivatives as potential XooFtsZ inhibitors through introducing the structure-based virtual screening (SBVS) approach and various biochemical methods. Notably, prepared compound B2, a 4'-acyloxy DMEP analog, had a 50% inhibitory concentration of 159.4 µM for inhibition of recombinant XooFtsZ GTPase, which was lower than that of the parent DMEP (278.0 µM). Compound B2 potently inhibited Xoo growth in vitro (minimum inhibitory concentration 153 mg L-1) and had 54.9% and 48.4% curative and protective control efficiencies against rice blight in vivo. Moreover, compound B2 also showed low toxicity for non-target organisms, including rice plant and mammalian cell. Given these interesting results, we provide a novel strategy to discover and optimize promising bactericidal compounds for the management of plant bacterial diseases.
Asunto(s)
Oryza , Xanthomonas , Antibacterianos/química , Proteínas Bacterianas/metabolismo , División Celular , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Podofilotoxina/metabolismo , Podofilotoxina/farmacología , Relación Estructura-ActividadRESUMEN
OBJECTIVE: To investigate the early predictors of necrotizing pneumonia in children. METHODS: The clinical data of 43 children with necrotizing pneumonia and 83 children with lobar pneumonia were retrospectively analyzed. Sex, age, the number of days with fever, laboratory examination results, and bronchoscopic findings were compared between the two groups. The multiple logistic regression analysis was used to identify the early predictors of necrotizing pneumonia. RESULTS: The necrotizing pneumonia group had a higher percentage of girls than the lobar pneumonia group (P<0.05). Compared with the lobar pneumonia group, the necrotizing pneumonia group had a larger number of days with fever, a higher peripheral blood white blood cell count (WBC), a higher percentage of neutrophils (NE%), and higher serum levels of high-sensitivity C-reactive protein (hs-CRP), albumin (Alb), and lactate dehydrogenase (LDH) (P<0.05). The necrotizing pneumonia group also had higher percentages of children with a large amount of sputum bolt under a bronchoscope which needed to be removed with biopsy forceps and children with rice-water-like bronchoalveolar lavage fluid (P<0.05). The multiple logistic regression analysis showed that being a female, the presence of sputum bolt under a bronchoscope which needed to be removed with biopsy forceps, the number of days with fever, WBC, hs-CRP, and LDH were independent predictors of necrotizing pneumonia. The receiver operating characteristic curve analysis showed that the cut-off values of the latter 4 predictors were 18.5â d, 15.1×10(9)/L, 121.5 mg/L, and 353.5 U/L, respectively. CONCLUSIONS: Increased WBC (≥15.1×10(9)/L), increased hs-CRP (≥121.5â mg/L), increased serum LDH (≥353.5 U/L), and the presence of sputum bolt under a bronchoscope which needs to be removed with biopsy forceps and rice-water-like bronchoalveolar lavage fluid may be the early predictors of necrotizing pneumonia in children.
Asunto(s)
Neumonía/diagnóstico , Proteína C-Reactiva/análisis , Niño , Preescolar , Femenino , Humanos , L-Lactato Deshidrogenasa/sangre , Recuento de Leucocitos , Modelos Logísticos , Masculino , Necrosis , Neumonía/sangreRESUMEN
BACKGROUND: Plant pathogens have led to large yield and quality losses in crops worldwide. The discovery and study of novel agrochemical alternatives based on the chemical modification of bioactive natural products is a highly efficient approach. Here, two series of novel cinnamic acid derivatives incorporating diverse building blocks with alternative linking patterns were designed and synthesized to identify their antiviral capacity and antibacterial activity. RESULTS: The bioassay results demonstrated that most cinnamic acid derivatives had excellent antiviral competence toward tobacco mosaic virus (TMV) in vivo, especially compound A5 (median effective concentration [EC50 ] = 287.7 µg mL-1 ), which had a notable protective effect against TMV when compared with the commercial virucide ribavirin (EC50 = 622.0 µg mL-1 ). In addition, compound A17 had a protective efficiency of 84.3% at 200 µg mL-1 against Xac in plants. Given these outstanding results, the engineered title compounds could be regarded as promising leads for controlling plant virus and bacterial diseases. Preliminary mechanistic studies suggest that compound A5 could enhance the host's defense responses by increasing the activity of defense enzymes and upregulating defense genes, thereby suppressing phytopathogen invasion. CONCLUSION: This research lays a foundation for the practical application of cinnamic acid derivatives containing diverse building blocks with alternative linking patterns in pesticide exploration. © 2023 Society of Chemical Industry.
Asunto(s)
Infecciones Bacterianas , Virus de Plantas , Virus del Mosaico del Tabaco , Humanos , Agroquímicos/farmacología , Antivirales/farmacología , Antivirales/química , Relación Estructura-Actividad , Diseño de Fármacos , Enfermedades de las Plantas/prevención & controlRESUMEN
Discovering new anti-virulent agents to control plant bacterial diseases by preventing bacterial pathogenesis/pathogenicity rather than affecting bacterial growth is a sensible strategy. However, the effects of compound-manipulated bacterial virulence factors on host response are still not clear. In this work, 35 new 1,3,4-oxadiazole derivatives were synthesized and systematically evaluated for their anti-phytopathogenic activities. Bioassay results revealed that compound C7 possessed outstanding antibacterial activity in vitro (half-maximal effective concentration: 0.80 µg/mL) against Xanthomonas oryzae pv. oryzae (Xoo) and acceptable bioactivity in vivo toward rice bacterial leaf blight. Furthermore, virulence factor-related biochemical assays showed that C7 was a promising anti-virulent agent. Interestingly, C7 could indirectly reduce the inducible expression of host SWEET genes and thereby alleviate nutrient supply in the infection process of phytopathogenic bacteria. Our results highlight the potential of 1,3,4-oxadiazole-based agrochemicals for manipulating type III secretion system-induced phytopathogenic bacteria starvation mechanisms to prevent plant bacterial diseases.
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Infecciones Bacterianas , Oryza , Xanthomonas , Sistemas de Secreción Tipo III/genética , Enfermedades de las Plantas/prevención & control , Enfermedades de las Plantas/microbiología , Oxadiazoles/farmacología , Oxadiazoles/química , Factores de Virulencia/metabolismo , Xanthomonas/genética , Oryza/metabolismo , Antibacterianos/químicaRESUMEN
Anti-infection strategies based on suppression of bacterial virulence factors represent a crucial direction for the development of new antibacterial agents to address the resistance triggered by traditional drugs'/pesticides' bactericidal activity. To identify and obtain more effective and diverse molecules targeting virulence, we prepared a series of 3-hydroxy-2-methyl-1-pyridin-4-(1H)-one derivatives and evaluated their antibacterial behaviors. Compound B6 exhibited the highest bioactivity, with half-maximal effective concentration (EC50) values ranging fro9m 10.03 to 30.16 µg mL-1 against three plant pathogenic bacteria. The antibacterial mechanism showed that it could considerably reduce various virulence factors (such as extracellular enzymes, biofilm, and T3SS effectors) and inhibit the expression of virulence factor-related genes. In addition, the control efficiency of compound B6 against rice bacterial leaf blight at 200 µg mL-1 was 46.15-49.15%, and their control efficiency was improved by approximately 12% after the addition of pesticide additives. Thus, a new class of bactericidal candidates targeting bacterial virulence factors was developed for controlling plant bacterial diseases.
Asunto(s)
Oryza , Plaguicidas , Xanthomonas , Enfermedades de las Plantas/microbiología , Antibacterianos/farmacología , Plaguicidas/farmacología , Oryza/microbiología , Factores de Virulencia/genética , Pruebas de Sensibilidad MicrobianaRESUMEN
BACKGROUND: Controlling bacterial infections in plants is a major challenge owing to the appearance of resistant strains. As a physical barrier, the bacterial biofilm helps bacterial infections acquire drug resistance by enabling bacteria to accommodate complex and volatile environmental conditions and avoid bactericidal effects. Thus, developing new antibacterial agents with antibiofilm potency is imperative. RESULTS: A series of simple triclosan derivatives containing isopropanolamine moiety were elaborately designed and assessed for their antibacterial behavior. Bioassay results showed that some title compounds had excellent bioactivity against three destructive bacteria Xanthomonas oryzae pv. oryzae (Xoo), Xanthomonas axonopodis pv. citri (Xac) and Pseudomonas syringae pv. actinidiae (Psa). Notably, compound C8 displayed high bioactivities toward Xoo and Xac, with EC50 values were 0.34 and 2.11 µg mL-1 , respectively. In vivo trials revealed that compound C8 exhibited excellent protective activities against rice bacterial blight and citrus bacterial canker at 200 µg mL-1 , with control effectivenesses of 49.57% and 85.60%, respectively. Compound A4 had remarkably inhibitory activity toward Psa, with an EC50 value of 2.63 µg mL-1 , and demonstrated outstanding protective activity with a value of 77.23% against Psa in vivo. Antibacterial mechanisms indicated that compound C8 dose-dependently prevented biofilm formation and extracellular polysaccharide production. C8 also significantly weakened the motility and pathogenicity of Xoo. CONCLUSION: This study contributes to the development and excavation of novel bactericidal candidates with broad-spectrum antibacterial activity by targeting bacterial biofilm to control refractory plant bacterial diseases. © 2023 Society of Chemical Industry.
Asunto(s)
Infecciones Bacterianas , Oryza , Triclosán , Xanthomonas , Triclosán/farmacología , Pruebas de Sensibilidad Microbiana , Oxadiazoles/química , Antibacterianos/farmacología , Antibacterianos/química , Enfermedades de las Plantas/prevención & control , Enfermedades de las Plantas/microbiologíaRESUMEN
Bacterial survival depends on membrane lipid homeostasis that enables to regulate lipid composition to adapt and optimize their growth in diverse environments. Therefore, the development of inhibitors that interfere with the bacterial fatty acid synthesis process is considered to be a promising tactic. In this study, 58 novel spirochromanone derivatives were prepared and their structure-activity relationship (SAR) was investigated. The bioassay results showed that all most of the compounds showed excellent biological activities, exampled by compounds B14, C1, B15, and B13, which had outstanding inhibitory activities toward various pathogenic bacteria with EC50 values of 0.78 µg/mL â¼3.48 µg/mL. Preliminary antibacterial behavior was studied by a series of biochemical assays including, but not limited to, fluorescence imaging patterns, GC-MS analysis, TEM images, and fluorescence titration experiments. Notably, compound B14 decreased the lipid content of the cell membrane, and increased cell membrane permeability, thereby destroying the integrity of the bacterial cell membrane. Further qRT-PCR results indicated that compound B14 interfered with the mRNA expression levels of fatty acid synthesis process-related genes including ACC, ACP, and Fab family genes. Herein, we highlight the promising bactericidal skeleton based on the spiro[chromanone-2,4'-piperidine]-4-one as a potential inhibitor of fatty acid synthesis.
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Bacterias , Piperidinas , Relación Estructura-Actividad , Ácidos Grasos/farmacología , Lípidos , Antibacterianos/química , Pruebas de Sensibilidad MicrobianaRESUMEN
Small cell lung cancer (SCLC) is a highly lethal subtype of lung cancer with few therapeutic options; therefore, the identification of new targets and drugs with potent combination therapy is desirable. We previously screened BH3 mimetics from a natural product library, and in this study, we validated nobiletin as a BH3 mimetic. Specifically, we observed its combination potential and mechanism with vorinostat in SCLC in vitro and in vivo. The results showed that combination treatment with nobiletin and vorinostat reduced the proliferation of SCLC H82 cells and increased the levels of apoptotic proteins such as cleaved caspase-9 and cleaved PARP. The combination treatment increased LC3-II expression and induced autophagic cell death. In addition, this treatment significantly inhibited H82 cell xenograft SCLC tumor growth in nude mice. The combination treatment with nobiletin and vorinostat efficiently increased autophagy by inhibiting the PI3K-AKT-mTOR pathway and promoting dissociation of the BCL-2 and Beclin 1 complex, increasing the level of isolated Beclin 1 to stimulate autophagy. Molecular docking and surface plasmon resonance analysis showed that nobiletin stably bound to the BCL-2, BCL-XL and MCL-1 proteins with high affinity in a concentration-dependent manner. These results suggest that nobiletin is a BH3-only protein mimetic. Furthermore, the combination of nobiletin with vorinostat increased histone H3K9 and H3K27 acetylation levels in SCLC mouse tumor tissue and enhanced the expression of the BH3-only proteins BIM and BID. We conclude that nobiletin is a novel natural BH3 mimetic that can cooperate with vorinostat to induce apoptosis and autophagy in SCLC.
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Neoplasias Pulmonares , Carcinoma Pulmonar de Células Pequeñas , Humanos , Animales , Ratones , Vorinostat/farmacología , Vorinostat/uso terapéutico , Carcinoma Pulmonar de Células Pequeñas/tratamiento farmacológico , Beclina-1 , Ratones Desnudos , Fosfatidilinositol 3-Quinasas , Simulación del Acoplamiento Molecular , Apoptosis , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/patología , Autofagia , Línea Celular TumoralRESUMEN
Flavanomarein (FM) is a major natural compound of Coreopsis tinctoria Nutt with protective effects against diabetic nephropathy (DN). In this study, we investigated the effects of FM on epithelial-mesenchymal transition (EMT) in high glucose (HG)-stimulated human proximal tubular epithelial cells (HK-2) and the underlying mechanisms, including both direct targets and downstream signal-related proteins. The influence of FM on EMT marker proteins was evaluated via western blot. Potential target proteins of FM were searched using Discovery Studio 2017 R2. Gene Ontology (GO) analysis was conducted to enrich the proteins within the protein-protein interaction (PPI) network for biological processes. Specific binding of FM to target proteins was examined via molecular dynamics and surface plasmon resonance analyses (SPR). FM promoted the proliferation of HK-2 cells stimulated with HG and inhibited EMT through the Syk/TGF-ß1/Smad signaling pathway. Spleen tyrosine kinase (Syk) was predicted to be the most likely directly interacting protein with FM. Combined therapy with a Syk inhibitor and FM presents significant potential as an effective novel therapeutic strategy for DN.
Asunto(s)
Transición Epitelial-Mesenquimal/efectos de los fármacos , Glucosa/farmacología , Quinasa Syk/metabolismo , Actinas/metabolismo , Cadherinas/metabolismo , Línea Celular , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Fibronectinas/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Riñón/citología , Simulación del Acoplamiento Molecular , Conformación Proteica , Transducción de Señal/efectos de los fármacos , Proteínas Smad/metabolismo , Quinasa Syk/química , Factor de Crecimiento Transformador beta1/metabolismo , Vimentina/metabolismoRESUMEN
OBJECTIVE: The importance of signal transduction in cell activities has been generally accepted. The purpose of this study was to analyze the regulatory effect of intracellular signaling cascade-associated genes on rat liver regeneration (LR) at transcriptional level. MATERIAL AND METHODS: The associated genes were originally obtained through a search of the databases and related scientific publications; their expression profiles were then checked in rat LR using the Rat Genome 230 2.0 array. The LR-associated genes were identified by comparing the discrepancy in gene expression changes between the partial hepatectomy (PH) group and the sham operation (SO) group. RESULTS: A total of 566 genes associated with the intracellular signaling cascade were LR related. The genes involved in nine signaling pathways including intracellular receptor-, second messenger-, nitric oxide-, hormone-, carbohydrate-mediated, protein kinase, small GTPase, ER-nuclear and target of rapamycin (TOR) signaling pathways were detected to be enriched in a cluster characterized by up-regulated expression in LR. According to their expression similarity and time relevance, they were separately classified into 5 and 5 groups. CONCLUSIONS: It is presumed that following PH, the second messenger-mediated signaling pathway inhibits the inflammatory response, while the protein kinase cascade and small GTPase-mediated signal transduction stimulate the immune response; the intracellular receptor-, second messenger-, small GTPase-mediated signal transduction and protein kinase cascade coordinately control cell replication; the intracellular receptor-, second messenger-mediated and ER-nuclear signaling pathways facilitate cell differentiation; the MAPK cascade and small GTPase-mediated signal transduction play a role in cytoskeletal reconstruction and cell migration; the second messenger-, small GTPase-mediated and IkappaB kinase/NFkappaB cascades take care of protein transport, etc., in LR.
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Péptidos y Proteínas de Señalización Intracelular/metabolismo , Regeneración Hepática/fisiología , Transducción de Señal/genética , Animales , Análisis por Conglomerados , Hepatectomía , Péptidos y Proteínas de Señalización Intracelular/genética , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Recuperación de la Función/fisiologíaAsunto(s)
Neumonía/terapia , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Necrosis , Neumonía/microbiología , Estudios RetrospectivosRESUMEN
The mechanism underlying acrylamide-induced neurotoxicity remains controversial. Previous studies have focused on acrylamide-induced toxicity in adult rodents, but neurotoxicity in weaning rats has not been investigated. To explore the neurotoxic effect of acrylamide on the developing brain, weaning rats were gavaged with 0, 5, 15, and 30 mg/kg acrylamide for 4 consecutive weeks. No obvious neurotoxicity was observed in weaning rats in the low-dose acrylamide group (5 mg/kg). However, rats from the moderate- and high-dose acrylamide groups (15 and 30 mg/kg) had an abnormal gait. Furthermore, biochemical tests in these rats demonstrated that glutamate concentration was significantly reduced, and γ-aminobutyric acid content was significantly increased and was dependent on acrylamide dose. Immunohistochemical staining showed that in the cerebral cortex, γ-aminobutyric acid, glutamic acid decarboxylase and glial fibrillary acidic protein expression increased remarkably in the moderate- and high-dose acrylamide groups. These results indicate that in weaning rats, acrylamide is positively associated with neurotoxicity in a dose-dependent manner, which may correlate with upregulation of γ-aminobutyric acid and subsequent neuronal degeneration after the initial acrylamide exposure.
RESUMEN
Haemangiopericytoma (HPC) is a rare vascular tumor with borderline malignancy, considerable histological variability, and unpredictable clinical and biological behavior. HPC can present a diagnostic challenge because of its indeterminate clinical, radiological, and pathological features. HPC generally presents in adulthood and is equally frequent in both sexes. HPC can arise in any site in the body as a slowly growing and painless mass. The precise cell type origin of HPC is uncertain. One third of HPCs occur in the head and neck areas. Exceptional cases of hemangioblastoma arising outside the head and neck areas have been reported, but little is known about their clinicopathologic and immunohistochemical features. This study reports on a case of a large sacro-anterior HPC in a 65-year-old male.