RESUMEN
Covalent organic frameworks (COFs), with the features of flexible structure regulation and easy introduction of functional groups, have aroused broad interest in the field of photocatalysis. However, due to the low light absorption intensity, low photoelectron conversion efficiency, and lack of suitable active sites, it remains a great challenge to achieve efficient photocatalytic aerobic oxidation reactions. Herein, based on reticular chemistry, we rationally designed a series of three-motif molecular junction type COFs, which formed dual photosensitizer coupled redox molecular junctions containing multifunctional COF photocatalysts. Significantly, due to the strong light adsorption ability of dual photosensitizer units and integrated oxidation and reduction features, the PY-BT COF exhibited the highest activity for photocatalytic aerobic oxidation. Especially, it achieved a photocatalytic benzylamine conversion efficiency of 99.9% in 2.5 h, which is much higher than that of the two-motif molecular junctions with only one photosensitizer or redox unit lacking COFs. The mechanism of selective aerobic oxidation was studied through comprehensive experiments and density functional theory calculations. The results showed that the photoinduced electron transfer occurred from PY and then through triphenylamine to BT. Furthermore, the thermodynamics energy for benzylamine oxidation on PY-BT COF was much lower than that for others, which confirmed the synergistic effect of dual photosensitizer coupled redox molecular junction COFs. This work provided a new strategy for the design of functional COFs with three-motif molecular junctions and also represented a new insight into the multifunctional COFs for organic catalytic reactions.
RESUMEN
The connectivity (valency) of building blocks for constructing 3D covalent organic frameworks (COFs) has long been limited to 4, 6, 8, and 12. Developing a higher connectivity remains a great challenge in the field of COF structural design. Herein, this work reports a hierarchical expansion strategy for making 16-connected building blocks to construct 3D COFs with sqc topology. The [16 + 2] construction achieved by condensation between a 16-connected carbazolyl dicyanobenzene-based building block (CzTPN) and linear diamino linkers (BD or Bpy) affords two 3D COFs (named CzBD COF and CzBpy COF). Furthermore, attributed to the well-organized donor-acceptor (D-A) heterojunction, the Ni chelated CzBpy COF (Ni@CzBpy COF) exhibits excellent performance for photoredox/Ni dual catalytic C(sp3)-C(sp2) cross-coupling of alkyltrifluoroborates with aryl halides, achieving a maximum 98% conversion and 94% yield for various substrates. This work developed the first case of high-connectivity COFs bearing 16-connected units, which is the highest connectivity reported until now, and achieved efficient photocatalysis applications, thus greatly enriching the possibilities of COFs.
RESUMEN
Extracellular vesicles (EVs) released by human induced pluripotent stem cell-derived neural stem cells (hiPSC-NSCs) are enriched with miRNAs and proteins capable of mediating robust antiinflammatory activity. The lack of tumorigenic and immunogenic properties and ability to permeate the entire brain to incorporate into microglia following intranasal (IN) administrations makes them an attractive biologic for curtailing chronic neuroinflammation in neurodegenerative disorders. We tested the hypothesis that IN administrations of hiPSC-NSC-EVs can alleviate chronic neuroinflammation and cognitive impairments induced by the peripheral lipopolysaccharide (LPS) challenge. Adult male, C57BL/6J mice received intraperitoneal injections of LPS (0.75 mg/kg) for seven consecutive days. Then, the mice received either vehicle (VEH) or hiPSC-NSC-EVs (~ 10 × 109 EVs/administration, thrice over 6 days). A month later, mice in all groups were investigated for cognitive function with behavioral tests and euthanized for histological and biochemical studies. Mice receiving VEH after LPS displayed deficits in associative recognition memory, temporal pattern processing, and pattern separation. Such impairments were associated with an increased incidence of activated microglia presenting NOD-, LRR-, and pyrin domain containing 3 (NLRP3) inflammasomes, elevated levels of NLRP3 inflammasome mediators and end products, and decreased neurogenesis in the hippocampus. In contrast, the various cognitive measures in mice receiving hiPSC-NSC-EVs after LPS were closer to naive mice. Significantly, these mice displayed diminished microglial activation, NLRP3 inflammasomes, proinflammatory cytokines, and a level of neurogenesis matching age-matched naïve controls. Thus, IN administrations of hiPSC-NSC-EVs are an efficacious approach to reducing chronic neuroinflammation-induced cognitive impairments.
Asunto(s)
Disfunción Cognitiva , Vesículas Extracelulares , Células Madre Pluripotentes Inducidas , Células-Madre Neurales , Humanos , Ratones , Masculino , Animales , Inflamasomas/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Células Madre Pluripotentes Inducidas/metabolismo , Enfermedades Neuroinflamatorias , Lipopolisacáridos/farmacología , Ratones Endogámicos NOD , Ratones Endogámicos C57BL , Inflamación/metabolismo , Vesículas Extracelulares/metabolismo , Microglía/metabolismo , Disfunción Cognitiva/etiología , Disfunción Cognitiva/prevención & control , Disfunción Cognitiva/metabolismo , Células-Madre Neurales/metabolismo , Hipocampo/metabolismo , NeurogénesisRESUMEN
Traumatic brain injury (TBI) leads to lasting brain dysfunction with chronic neuroinflammation typified by nucleotide-binding domain leucine-rich repeat and pyrin domain-containing receptor 3 (NLRP3) inflammasome activation in microglia. This study probed whether a single intranasal (IN) administration of human mesenchymal stem cell-derived extracellular vesicles (hMSC-EVs) naturally enriched with activated microglia-modulating miRNAs can avert chronic adverse outcomes of TBI. Small RNA sequencing confirmed the enrichment of miRNAs capable of modulating activated microglia in hMSC-EV cargo. IN administration of hMSC-EVs into adult mice ninety minutes after the induction of a unilateral controlled cortical impact injury resulted in their incorporation into neurons and microglia in both injured and contralateral hemispheres. A single higher dose hMSC-EV treatment also inhibited NLRP3 inflammasome activation after TBI, evidenced by reduced NLRP3, apoptosis-associated speck-like protein containing a CARD, activated caspase-1, interleukin-1 beta, and IL-18 levels in the injured brain. Such inhibition in the acute phase of TBI endured in the chronic phase, which could also be gleaned from diminished NLRP3 inflammasome activation in microglia of TBI mice receiving hMSC-EVs. Proteomic analysis and validation revealed that higher dose hMSC-EV treatment thwarted the chronic activation of the p38 mitogen-activated protein kinase (MAPK) signaling pathway by IL-18, which decreased the release of proinflammatory cytokines. Inhibition of the chronic activation of NLRP3-p38/MAPK signaling after TBI also prevented long-term cognitive and mood impairments. Notably, the animals receiving higher doses of hMSC-EVs after TBI displayed better cognitive and mood function in all behavioral tests than animals receiving the vehicle after TBI. A lower dose of hMSC-EV treatment also partially improved cognitive and mood function. Thus, an optimal IN dose of hMSC-EVs naturally enriched with activated microglia-modulating miRNAs can inhibit the chronic activation of NLRP3-p38/MAPK signaling after TBI and prevent lasting brain dysfunction.
Asunto(s)
Lesiones Traumáticas del Encéfalo , Vesículas Extracelulares , MicroARNs , Proteína Quinasa 14 Activada por Mitógenos , Animales , Humanos , Ratones , Encéfalo/metabolismo , Lesiones Traumáticas del Encéfalo/metabolismo , Vesículas Extracelulares/metabolismo , Inflamasomas/metabolismo , Interleucina-18/metabolismo , MicroARNs/metabolismo , Proteína Quinasa 14 Activada por Mitógenos/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Proteómica , Transducción de Señal , Células Madre MesenquimatosasRESUMEN
AIMS: The aim of this study was to develop a population pharmacokinetic (PK) model to simultaneously describe both total and unbound concentrations of ciprofol and its major glucuronide metabolite, M4, and to link it to the population pharmacodynamics (PD) model in subjects with various renal functions. METHODS: A total of 401 and 459 pairs of total and unbound plasma concentrations of ciprofol and M4, respectively, as well as 2190 bispectral index (BIS) data from 24 Chinese subjects with various renal functions were available. Covariates that may potentially contribute to the PK and PD variability of ciprofol were screened using a stepwise procedure. The optimal ciprofol induction dosing regimen was determined by model-based simulations. RESULTS: The PK of unbound ciprofol could best be described by a three-compartment model, while a two-compartment model could adequately describe unbound M4 PK. The concentrations of total and unbound ciprofol and M4 were linked using a linear protein binding model. The relationship between plasma concentrations of ciprofol and BIS data was best described by an inhibitory sigmoidal Emax model with a two-compartment biophase distribution compartment. Hemoglobin was the identified covariate determining the central compartment clearance of ciprofol; uric acid was a covariate affecting the central compartment clearance of M4 and protein binding rate, kB . The included covariates had no effect on the PD of ciprofol. Simulation results indicated that the label-recommended dose regimen was adequate for anaesthesia induction. CONCLUSIONS: The developed model fully characterized the population PK and PD profiles of ciprofol. No dose adjustment is required in patients with mild and moderate renal impairment.
Asunto(s)
Riñón , Modelos Biológicos , Humanos , Relación Dosis-Respuesta a Droga , Riñón/fisiologíaRESUMEN
The introduction of signal amplification to molecular spectral sensing systems is an intriguing topic in supramolecular analytical chemistry. In this study, click chemistry was used to generate a triazole moiety to bridge with a long hydrophobic alkyl chain (Cn) and another short alkyl chain (Cm) bearing a 1,4,7-triazacyclonane (TACN) group for efficiently generating a self-assembling multivalent catalyst, Cn-triazole-Cm-TACN·Zn2+ (n and m represent the carbon numbers of both alkyl chains, respectively; n = 16, 18, and 20; m = 2 and 6), to catalyze the hydrolysis of 2-hydroxypropyl-4-nitrophenyl phosphate (HPNPP) when Zn2+ was added. The triazole moiety introduced adjacent to the TACN group plays an important role in improving the selectivity of Zn2+ because the triazole moiety can participate in the coordination interaction between the Zn2+ and neighboring TACN group. The supplementary triazole complexing increases the space requirement for coordinated metal ions. This catalytic sensing system also shows high sensitivity, with a favorable limit of detection down to 350 nM, even if only UV-vis absorption spectra rather than more sensitive fluorescence techniques were used for signaling, and can be used to determine the concentration of Zn2+ in tap water, which demonstrates the practical application feasibility.
RESUMEN
The prevention of fungal proliferation in postharvest grains is critical for maintaining grain quality and reducing mycotoxin contamination. Fumigation with natural gaseous fungicides is a promising and sustainable approach to protect grains from fungal spoilage. In this study, the antifungal activities of (E)-2-alkenals (C5-C10) on Aspergillus flavus were tested in the vapor phase, and (E)-2-heptenal showed the highest antifungal activity against A. flavus. (E)-2-Heptenal completely inhibited A. flavus growth at 0.0125 µL/mL and 0.2 µL/mL in the vapor phase and liquid contact, respectively. (E)-2-Heptenal can disrupt the plasma membrane integrity of A. flavus via leakage of intracellular electrolytes. Scanning electron microscopy indicated that the mycelial morphology of A. flavus was remarkably affected by (E)-2-heptenal. Metabolomic analyses indicated that 49 metabolites were significantly differentially expressed in A. flavus mycelia exposed to 0.2 µL/mL (E)-2-heptenal; these metabolites were mainly involved in galactose metabolism, starch and sucrose metabolism, the phosphotransferase system, and ATP-binding cassette transporters. ATP production was reduced in (E)-2-heptenal-treated A. flavus, and Janus Green B staining showed reduced cytochrome c oxidase activity. (E)-2-Heptenal treatment induced oxidative stress in A. flavus mycelia with an accumulation of superoxide anions and hydrogen peroxide and increased activities of superoxide dismutase and catalase. Simulated storage experiments showed that fumigation with 400 µL/L of (E)-2-heptenal vapor could completely inhibit A. flavus growth in wheat grains with 20% moisture; this demonstrates its potential use in preventing grain spoilage. This study provides valuable insights into understanding the antifungal effects of (E)-2-heptenal on A. flavus. KEY POINTS : ⢠(E)-2-Heptenal vapor showed the highest antifungal activity against A. flavus among (C5-C10) (E)-2-alkenals. ⢠The antifungal effects of (E)-2-heptenal against A. flavus were determined. ⢠The antifungal actions of (E)-2-heptenal on A. flavus were revealed by metabolomics and biochemical analyses.
Asunto(s)
Antifúngicos , Aspergillus flavus , Antifúngicos/farmacología , Antifúngicos/metabolismo , Aldehídos/metabolismo , MetabolómicaRESUMEN
Plant volatile compounds have great potential for preventing and controlling fungal spoilage in post-harvest grains. Recently, we have reported the antifungal effects of trans-anethole, the main volatile constituent of the Illicium verum fruit, on Aspergillus flavus. In this study, the inhibitory mechanisms of trans-anethole against the growth of A. flavus mycelia were investigated using transcriptomic and biochemical analyses. Biochemical and transcriptomic changes in A. flavus mycelia were evaluated after exposure to 0.2 µL/mL trans-anethole. Scanning electron microscopy showed that trans-anethole treatment resulted in the surface wrinkling of A. flavus mycelia, and calcofluor white staining confirmed that trans-anethole treatment disrupted the mycelial cell wall structure. Annexin V-fluorescein isothiocyanate/propidium iodide double staining suggested that trans-anethole induced apoptosis in A. flavus mycelia. Reduced mitochondrial membrane potential and DNA damage were observed in trans-anethole-treated A. flavus mycelia using 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl-imidacarbocyanine and 4',6-diamidino-2-phenylindole staining, respectively. 2',7'- Dichloro-dihydro-fluorescein diacetate staining and biochemical assays demonstrated that trans-anethole treatment cause the accumulation of reactive oxygen species in the A. flavus mycelia. Transcriptome results showed that 1673 genes were differentially expressed in A. flavus mycelia exposed to trans-anethole, which were mainly associated with multidrug transport, oxidative phosphorylation, citric acid cycle, ribosomes, and cyclic adenosine monophosphate signaling. We propose that trans-anethole can inhibit the growth of A. flavus mycelia by disrupting the cell wall structure, blocking the multidrug transport process, disturbing the citric acid cycle, and inducing apoptosis. This study provides new insights into the inhibitory mechanism of trans-anethole on A. flavus mycelia and will be helpful for the development of natural fungicides. KEY POINTS: ⢠Biochemical analyses of A. flavus mycelia exposed to trans-anethole were performed ⢠Transcriptomic changes in trans-anethole-treated A. flavus mycelia were analyzed ⢠An inhibitory mechanism of trans-anethole on the growth of A. flavus mycelia was proposed.
Asunto(s)
Derivados de Alilbenceno , Antifúngicos , Antifúngicos/química , Aspergillus flavus , Transcriptoma , Derivados de Alilbenceno/metabolismo , Derivados de Alilbenceno/farmacologíaRESUMEN
Fungal spoilage of postharvest grains poses serious problems with respect to food safety, human health, and the economic value of grains. The protection of cereal grains from deleterious fungi is a critical aim in postharvest grain management. Considering the bulk volume of grain piles in warehouses or bins and food safety, fumigation with natural gaseous fungicides is a promising strategy to control fungal contamination on postharvest grains. Increasing research has focused on the antifungal properties of biogenic volatiles. This review summarizes the literature related to the effects of biogenic volatiles from microbes and plants on spoilage fungi on postharvest grains and highlights the underlying antifungal mechanisms. Key areas for additional research on fumigation with biogenic volatiles in postharvest grains are noted. The research described in this review supports the protective effects of biogenic volatiles against grain spoilage by fungi, providing a basis for their expanded application in the management of postharvest grains.
Asunto(s)
Hongos , Fungicidas Industriales , Humanos , Antifúngicos/farmacología , Fungicidas Industriales/farmacología , Grano Comestible/microbiologíaRESUMEN
The high local electron density and efficient charge carrier separation are two important factors to affect photocatalytic activity, especially for the CO2 photoreduction reaction. However, the systematic studies on the structure-functional relationship regarding the above two factors based on precisely structure model are rarely reported. Herein, as a proof-of-concept, we developed a new strategy on the evaluation of local electron density by controlling the relative electron-deficient (ED) and electron-rich (ER) intensity of monomer at a molecular level based on three rational-designed vinylene-linked sp2 carbon-covalent organic frameworks (COFs). As expected, the as-prepared vinylene-linked sp2 carbon-conjugated metal-covalent organic framework (MCOFs) (VL-MCOF-1) with molecular junction exhibited excellent activities for CO2 -to-HCOOH conversion (283.41â µmol g-1 h-1 ) and high selectivity of 97.1 %, much higher than the VL-MCOF-2 and g-C34 N6 -COF, which is due to the synergistic effect of the multi-electronic metal clusters (Cu3 (PyCA)3 ) (PyCA=pyrazolate-4-carboxaldehyde) as strong ER roles and cyanopyridine units as ED roles and active sites, as well as the boosted photo-induced charge separation efficiency of vinyl connection and increased light utilization ability. These results not only provide a strategy for regulating the electron-density distribution of photocatalysts at the molecular level but also offers profound insights for metal clusters-based COFs to effective CO2 conversion.
RESUMEN
In this work, we innovatively assembled two types of traditional photosensitizers, that is pyridine ruthenium/ferrum (Ru(bpy)3 2+ /Fe(bpy)3 2+ ) and porphyrin/metalloporphyrin complex (2HPor/ZnPor) by covalent linkage to get a series of dual photosensitizer-based three-dimensional metal-covalent organic frameworks (3D MCOFs), which behaved strong visible light-absorbing ability, efficient electron transfer and suitable band gap for highly efficient photocatalytic hydrogen (H2 ) evolution. Rubpy-ZnPor COF achieved the highest H2 yield (30 338â µmol g-1 h-1 ) with apparent quantum efficiency (AQE) of 9.68 %@420â nm, which showed one of the best performances among all reported COF based photocatalysts. Furthermore, the in situ produced H2 was successfully tandem used in the alkyne hydrogenation with ≈99.9 % conversion efficiency. Theoretical calculations reveal that both the two photosensitizer units in MCOFs can be photoexcited and thus contribute optimal photocatalytic activity. This work develops a general strategy and shows the great potential of using multiple photosensitive materials in the field of photocatalysis.
RESUMEN
PURPOSE: Venetoclax (VEN), an anti-tumor drug that is a substrate of cytochrome P450 3A enzyme (CYP3A4), is used to treat leukemia. Voriconazole (VCZ) is an antifungal medication that inhibits CYP3A4. The goal of this study is to predict the effect of VCZ on VEN exposure. METHOD: Two physiological based pharmacokinetics (PBPK) models were developed for VCZ and VEN using the bottom-up and top-down method. VCZ model was also developed to describe the effect of CYP2C19 polymorphism on its pharmacokinetics (PK). The reversible inhibition constant (Ki) of VCZ for CYP3A4 was calibrated using drug-drug interaction (DDI) data of midazolam and VCZ. The clinical verified VCZ and VEN model were used to predict the DDI of VCZ and VEN at clinical dosing scenario. RESULT: VCZ model predicted VCZ exposure in the subjects of different CYP2C19 genotype and DDI related fold changes of sensitive CYP3A substrate with acceptable prediction error. VEN model can capture PK of VEN with acceptable prediction error. The DDI PBPK model predicted that VCZ increased the exposure of VEN by 4.5-9.6 fold. The increase in VEN exposure by VCZ was influenced by subject's CYP2C19 genotype. According to the therapeutic window, VEN dose should be reduced to 100 mg when co-administered with VCZ. CONCLUSION: The PBPK model developed here could support individual dose adjustment of VEN and DDI risk assessment. Predictions using the robust PBPK model confirmed that the 100 mg dose adjustment is still applicable in the presence of VCZ with high inter-individual viability.
Asunto(s)
Compuestos Bicíclicos Heterocíclicos con Puentes , Citocromo P-450 CYP3A , Modelos Biológicos , Sulfonamidas , Voriconazol , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacocinética , Citocromo P-450 CYP2C19/genética , Citocromo P-450 CYP3A/genética , Inhibidores del Citocromo P-450 CYP3A/farmacocinética , Interacciones Farmacológicas , Humanos , Sulfonamidas/farmacocinética , Voriconazol/farmacocinéticaRESUMEN
Methods of controlling Aspergillus flavus contamination in agro-products have attracted attention because of its impact on global food security. We previously reported that the natural cereal volatile heptanal could effectively inhibit A. flavus growth and showed great potential as a bio-preservative agent. In this study, the minimum inhibitory concentration and minimum fungicide concentration of heptanal could change the surface morphology of A. flavus spores, causing them to wrinkle and collapse. Transcriptomic analysis showed that heptanal treatment significantly changed the expression of several genes involved in cell wall and plasma damage, reactive oxygen species (ROS) accumulation, energy metabolism, AMPK-activated protein kinase, biosynthesis of unsaturated fatty acids, RNA degradation, and DNA replication. Heptanal-induced early apoptosis of A. flavus spores was characterized by decreased mitochondrial membrane potential, increased intracellular ROS production, and DNA fragmentation. This study provides new insight into the inhibitory mechanism of heptanal against A. flavus and points to its potential application as a bio-preservative. KEY POINTS: ⢠Heptanal can effectively inhibit A. flavus growth in cereal grains. ⢠The transcriptional changes in A. flavus spores exposed to heptanal were analyzed. ⢠The antifungal mechanism of heptanal against A. flavus was elucidated.
Asunto(s)
Aldehídos , Aspergillus flavus , Antifúngicos , Aspergillus flavus/genética , Perfilación de la Expresión Génica , Esporas FúngicasRESUMEN
Biogenic volatile organic compounds hold remarkable potential for controlling fungal decay in agro- and food products. Recently, we reported that linalool, the major volatile component of the Zanthoxylum schinifolium pericarp, showed great potential as a biofumigant to control Aspergillus flavus growth in postharvest grains. In this study, the inhibitory effects of linalool on A. flavus growth in stored grains and its underlying mechanism were investigated through transcriptomic and biochemical analyses. Linalool vapor at 800 µL/L can effectively prevent A. flavus growth in 22% moisture wheat grains. Linalool at 2 µL/mL completely inhibited the germination of A. flavus spores, and 10 µL/mL caused spore death. Scanning electron microscopy revealed that linalool treatment caused wrinkling and spore breakage. Transcriptomics showed that 3806 genes were significantly differentially expressed in A. flavus spores exposed to 2 µL/mL linalool, predominantly showing enrichment regarding the ribosome, DNA replication, glutathione metabolism, peroxisome, and MAPK signaling pathways. Flow cytometry showed that linalool treatment caused hyperpolarization of mitochondrial membrane potential. 4,6-Diamidino-2-phenylindole staining indicated that linalool caused DNA fragmentation in A. flavus spores, and monodansylcadaverine staining confirmed that linalool induced autophagy in A. flavus spores. We thus propose that linalool can damage the plasma membrane, cause mitochondrial dysfunction and DNA damage, and induce autophagy in A. flavus spores. These findings considerably improve our understanding of the mechanisms underlying the inhibitory effects of linalool on A. flavus, which is crucial regarding the development of applications to prevent postharvest grain spoilage due to A. flavus infestations. KEY POINTS: ⢠The inhibitory potency of linalool on A. flavus spore germination was determined. ⢠Transcriptomic analyses were performed to identify differentially expressed genes of A. flavus exposed to linalool. ⢠A functional mechanism underlying the inhibitory effects of linalool on A. flavus spore germination is proposed.
Asunto(s)
Aspergillus flavus , Compuestos Orgánicos Volátiles , Monoterpenos Acíclicos , Antifúngicos/farmacología , Glutatión/metabolismo , Esporas Fúngicas , Compuestos Orgánicos Volátiles/metabolismoRESUMEN
The exploitation of active ingredients from plant volatile organic compounds as natural gaseous fungicides shows remarkable potential for controlling fungal decay in postharvest agroproducts. Although 1-octanol is a common component of cereal volatiles, its antifungal potency against spoilage fungi in postharvest grains remains unclear. In this study, we studied the effectiveness of 1-octanol against Aspergillus flavus growth in postharvest grains and its mechanisms of action. 1-Octanol vapor and liquid contact dose-dependently inhibited A. flavus spore germination and mycelial growth at a low concentration. The simulated storage experiment demonstrated that 300 µL/L of 1-octanol vapor completely controlled A. flavus growth in wheat, corn, and paddy grains with 20% moisture content. 1-Octanol treatment irreversibly damaged the conidial and mycelial morphology of A. flavus and caused electrolyte leakage due to reduced plasma membrane integrity. It induced apoptosis along with morphological abnormalities, phosphatidylserine externalization, mitochondrial membrane potential depolarization, intracellular reactive oxygen species accumulation, and DNA fragmentation in A. flavus cells. Metabolomic analysis revealed that 1-octanol treatment disrupted the biosynthesis of unsaturated fatty acids, ATP-binding cassette transporters, amino acid metabolism, and glycerophospholipid metabolism. This study demonstrated the promising application potential of 1-octanol as a biofumigant for preventing fungal spoilage of postharvest cereal grains. KEY POINTS: ⢠(1) 1-Octanol inhibits Aspergillus flavus growth in the vapor phase and liquid contact; ⢠(2) 1-Octanol damages membrane integrity and induces apoptosis of A. flavus; ⢠(3) Metabolomic changes in A. flavus mycelia were analyzed after 1-octanol treatment.
Asunto(s)
Aspergillus flavus , Fungicidas Industriales , 1-Octanol/metabolismo , 1-Octanol/farmacología , Antifúngicos/química , Fungicidas Industriales/farmacología , Esporas FúngicasRESUMEN
The exploitation of plant volatile organic compounds as biofumigants to control postharvest decaying of agro-products has received considerable research attention. Our previous study reported that 1-nonanol, the main constituent of cereal volatiles, can inhibit Aspergillus flavus growth and has the potential as a biofumigant to control the fungal spoilage of cereal grains. However, the antifungal mechanism of 1-nonanol against A. flavus is still unclear at the molecular level. In this study, the minimum inhibitory concentration and minimum fungicidal concentration of 1-nonanol against A. flavus spores were 2 and 4 µL/mL, respectively. Scanning electron microscopy revealed that the 1-nonanol can distort the morphology of A. flavus spore. Annexin V-FITC/PI double staining showed that 1-nonanol induced phosphatidylserine eversion and increased membrane permeability of A. flavus spores. Transcriptional profile analysis showed that 1-nonanol treatment mainly affected the expression of genes related to membrane damage, oxidative phosphorylation, blockage of DNA replication, and autophagy in A. flavus spores. Flow cytometry analysis showed that 1-nonanol treatment caused hyperpolarization of mitochondrial membrane potential and accumulation of reactive oxygen species in A. flavus spores. 4',6-diamidino-2-phenylindole staining showed that treatment with 1-nonanol destroyed the DNA. Biochemical analysis results confirmed that 1-nonanol exerted destructive effects on A. flavus spores by decreasing intracellular adenosine triphosphate content, reducing mitochondrial ATPase activity, accumulating hydrogen peroxide and superoxide anions, and increasing catalase and superoxide dismutase enzyme activities. This study provides new insights into the antifungal mechanisms of 1-nonanol against A. flavus. KEY POINTS: ⢠1-Nonanol treatment resulted in abnormal morphology of A. flavus spores. ⢠1-Nonanol affects the expression of key growth-related genes of A. flavus. ⢠The apoptosis of A. favus spores were induced after exposed to 1-nonanol.
Asunto(s)
Aspergillus flavus , Transcriptoma , Antifúngicos/metabolismo , Antifúngicos/farmacología , Aspergillus flavus/metabolismo , Alcoholes Grasos/metabolismo , Esporas FúngicasRESUMEN
Medial ganglionic eminence (MGE)-like interneuron precursors derived from human induced pluripotent stem cells (hiPSCs) are ideal for developing patient-specific cell therapy in temporal lobe epilepsy (TLE). However, their efficacy for alleviating spontaneous recurrent seizures (SRS) or cognitive, memory, and mood impairments has never been tested in models of TLE. Through comprehensive video- electroencephalographic recordings and a battery of behavioral tests in a rat model, we demonstrate that grafting of hiPSC-derived MGE-like interneuron precursors into the hippocampus after status epilepticus (SE) greatly restrained SRS and alleviated cognitive, memory, and mood dysfunction in the chronic phase of TLE. Graft-derived cells survived well, extensively migrated into different subfields of the hippocampus, and differentiated into distinct subclasses of inhibitory interneurons expressing various calcium-binding proteins and neuropeptides. Moreover, grafting of hiPSC-MGE cells after SE mediated several neuroprotective and antiepileptogenic effects in the host hippocampus, as evidenced by reductions in host interneuron loss, abnormal neurogenesis, and aberrant mossy fiber sprouting in the dentate gyrus (DG). Furthermore, axons from graft-derived interneurons made synapses on the dendrites of host excitatory neurons in the DG and the CA1 subfield of the hippocampus, implying an excellent graft-host synaptic integration. Remarkably, seizure-suppressing effects of grafts were significantly reduced when the activity of graft-derived interneurons was silenced by a designer drug while using donor hiPSC-MGE cells expressing designer receptors exclusively activated by designer drugs (DREADDs). These results implied the direct involvement of graft-derived interneurons in seizure control likely through enhanced inhibitory synaptic transmission. Collectively, the results support a patient-specific MGE cell grafting approach for treating TLE.
Asunto(s)
Encéfalo/embriología , Epilepsia/cirugía , Hipocampo/cirugía , Células Madre Pluripotentes Inducidas/trasplante , Estado Epiléptico/cirugía , Afecto , Animales , Región CA1 Hipocampal/fisiología , Cognición , Giro Dentado/fisiología , Epilepsia del Lóbulo Temporal/cirugía , Humanos , Masculino , Ratas , Ratas Endogámicas F344 , Convulsiones/cirugía , Sinapsis/fisiologíaRESUMEN
Persistent cognitive and mood impairments in Gulf War Illness (GWI) are associated with chronic neuroinflammation, typified by hypertrophied astrocytes, activated microglia, and increased proinflammatory mediators in the brain. Using a rat model, we investigated whether a simple lifestyle change such as moderate voluntary physical exercise would improve cognitive and mood function in GWI. Because veterans with GWI exhibit fatigue and post-exertional malaise, we employed an intermittent voluntary running exercise (RE) regimen, which prevented exercise-induced stress. The GWI rats were provided access to running wheels three days per week for 13 weeks, commencing ten weeks after the exposure to GWI-related chemicals and stress (GWI-RE group). Groups of age-matched sedentary GWI rats (GWI-SED group) and naïve rats were maintained parallelly. Interrogation of rats with behavioral tests after the 13-week RE regimen revealed improved hippocampus-dependent object location memory and pattern separation function and reduced anxiety-like behavior in the GWI-RE group compared to the GWI-SED group. Moreover, 13 weeks of RE in GWI rats significantly reversed activated microglia with short and less ramified processes into non-inflammatory/antiinflammatory microglia with highly ramified processes and reduced the hypertrophy of astrocytes. Moreover, the production of new neurons in the hippocampus was enhanced when examined eight weeks after the commencement of RE. Notably, increased neurogenesis continued even after the cessation of RE. Collectively, the results suggest that even a moderate, intermittent physical exercise has the promise to improve brain function in veterans with GWI in association with suppression of neuroinflammation and enhancement of hippocampal neurogenesis.
Asunto(s)
Síndrome del Golfo Pérsico , Animales , Astrocitos , Cognición , Hipocampo , Microglía , Neurogénesis , RatasRESUMEN
Gulf War Illness (GWI) is a chronic, multi-symptom disorder affecting approximately 30 percent of the nearly 700,000 Veterans of the 1991 Persian Gulf War. GWI-related chemical (GWIC) exposure promotes immune activation that correlates with cognitive impairment and other symptoms of GWI. However, the molecular mechanisms and signaling pathways linking GWIC to inflammation and neurological symptoms remain unclear. Here we show that acute exposure of murine macrophages to GWIC potentiates innate immune signaling and inflammatory cytokine production. Using an established mouse model of GWI, we report that neurobehavioral changes and neuroinflammation are attenuated in mice lacking the cyclic GMP-AMP synthase (cGAS)-Stimulator of Interferon Genes (STING) and NOD-, LRR- or pyrin domain-containing protein 3 (NLRP3) innate immune pathways. In addition, we report sex differences in response to GWIC, with female mice showing more pronounced cognitive impairment and hippocampal astrocyte hypertrophy. In contrast, male mice display a GWIC-dependent upregulation of proinflammatory cytokines in the plasma that is not present in female mice. Our results indicate that STING and NLRP3 are key mediators of the cognitive impairment and inflammation observed in GWI and provide important new information on sex differences in this model.
Asunto(s)
Disfunción Cognitiva , Síndrome del Golfo Pérsico , Animales , Femenino , Guerra del Golfo , Masculino , Ratones , Ratones Endogámicos NOD , NeuroinmunomodulaciónRESUMEN
Hexanal, a natural volatile organic compound, exerts antifungal activity against Aspergillus flavus; however, the mechanisms underlying these effects are unclear. In this study, we found that the growth of A. flavus mycelium was completely inhibited following exposure to 0.4 µL/mL hexanal (minimal inhibitory concentration). A detailed metabolomics survey was performed to identify changes in metabolite production by A. flavus cells after exposure to 1/2 the minimal inhibitory concentration of hexanal for 6 h, which revealed significant differences in 70 metabolites, including 20 upregulated and 50 downregulated metabolites. Among them, levels of L-malic acid, α-linolenic acid, phosphatidylcholine, D-ribose, riboflavin, D-mannitol, D-sorbitol, and deoxyinosine were significantly reduced. The metabolomics results suggest that the metabolites are mainly involved in the tricarboxylic acid cycle (TCA), ABC transport system, and membrane synthesis in A. flavus cells. Hexanal treatment reduced succinate dehydrogenase and mitochondrial dehydrogenase activity and stimulated superoxide anion and hydrogen peroxide accumulation in A. flavus mycelia. Increases in the electric conductivity and A260nm of the culture supernatant indicated cell membrane leakage. Therefore, hexanal appears to disrupt cell membrane synthesis, induce mitochondrial dysfunction, and increase oxidative stress in A. flavus mycelia. KEY POINTS: ⢠Metabolite changes of A. flavus mycelia were identified after hexanal treatment. ⢠Most differential metabolites were downregulated in hexanal-treated A. flavus. ⢠An antifungal model of hexanal against A. flavus was proposed.