Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 614
Filtrar
1.
Behav Brain Res ; 471: 115117, 2024 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-38908485

RESUMEN

INTRODUCTION: Neuro-navigated repetitive transcranial magnetic stimulation (rTMS) of the left angular gyrus has been broadly investigated for the treatment of amnestic mild cognitive impairment (aMCI). Although abnormalities in two hippocampal networks, the anterior-temporal (AT) and posterior-medial (PM) networks, are consistent with aMCI and are potential therapeutic targets for rTMS, the underlying mechanisms of the therapeutic effects of rTMS on hippocampal network connections remain unknown. Here, we assessed the impact of left angular gyrus rTMS on activity in these networks and explored whether the treatment response was due to the distance between the clinically applied target (the group average optimal site) and the personalized target in patients with aMCI. METHODS: Sixty subjects clinically diagnosed with aMCI participated in this study after 20 sessions of sham-controlled rTMS targeting the left angular gyrus. Resting-state functional magnetic resonance imaging and neuropsychological assessments were performed before and after rTMS. Functional connectivity alterations in the PM and AT networks were assessed using seed-based functional connectivity analysis and two-factor repeated measures analysis of variance (ANOVA). We then computed the correlations between the functional connectivity changes and clinical rating scales. Finally, we examined whether the Euclidean distance between the clinically applied and personalized targets predicted the subsequent treatment response. RESULTS: Compared with the sham group, the active rTMS group showed rTMS-induced deactivation of functional connectivity within the medial temporal lobe-AT network, with a negative correlation with episodic memory score changes. Moreover, the active rTMS lowers the interdependency of changes in the PM and AT networks. Finally, the Euclidean distance between the clinically applied and personalized target distances could predict subsequent network lever responses in the active rTMS group. CONCLUSIONS: Neuro-navigated rTMS selectively modulates widespread functional connectivity abnormalities in the PM and AT hippocampal networks in aMCI patients, and the modulation of hippocampal-AT network connectivity can efficiently reverse memory deficits. The results also highlight the necessity of personalized targets for fMRI.

2.
Bioresour Technol ; 406: 131053, 2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-38944318

RESUMEN

Lignocellulose presents a promising alternative to fossil fuels. Monitoring the mass and size changes of lignocellulosic particles without disrupting the process can assist in adjusting pretreatment and enzymatic hydrolysis, where conventional sieving methods fall short. A method utilizing focused beam reflectance measurement (FBRM) was developed to establish mathematical correlations between FBRM chord information (chord length and count) and particle characteristics (weight and size) quantified through sieving. Results indicate particle size exhibits a linear correlation with the square weighted median chord length (Lsqr) with R2 at 0.93. Further, real-time bulk particle mass can be predicted using Lsqr and chord count (R2 0.98). These correlations are applicable in range 53 µm to 358.5 µm. Real-time monitoring of enzymatic hydrolysis of corn stalks has demonstrated the practical applicability of FBRM. This study introduces a novel approach for online characterization of lignocellulosic particles, thereby enhancing lignocellulosic biorefineries.

3.
Nat Microbiol ; 9(7): 1686-1699, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38898217

RESUMEN

The continuing emergence of invasive fungal pathogens poses an increasing threat to public health. Here, through the China Hospital Invasive Fungal Surveillance Net programme, we identified two independent cases of human infection with a previously undescribed invasive fungal pathogen, Rhodosporidiobolus fluvialis, from a genus in which many species are highly resistant to fluconazole and caspofungin. We demonstrate that R. fluvialis can undergo yeast-to-pseudohyphal transition and that pseudohyphal growth enhances its virulence, revealed by the development of a mouse model. Furthermore, we show that mouse infection or mammalian body temperature induces its mutagenesis, allowing the emergence of hypervirulent mutants favouring pseudohyphal growth. Temperature-induced mutagenesis can also elicit the development of pan-resistance to three of the most commonly used first-line antifungals (fluconazole, caspofungin and amphotericin B) in different Rhodosporidiobolus species. Furthermore, polymyxin B was found to exhibit potent activity against the pan-resistant Rhodosporidiobolus mutants. Collectively, by identifying and characterizing a fungal pathogen in the drug-resistant genus Rhodosporidiobolus, we provide evidence that temperature-dependent mutagenesis can enable the development of pan-drug resistance and hypervirulence in fungi, and support the idea that global warming can promote the evolution of new fungal pathogens.


Asunto(s)
Antifúngicos , Mutagénesis , Animales , Ratones , Humanos , Virulencia/genética , Antifúngicos/farmacología , China , Temperatura Corporal , Modelos Animales de Enfermedad , Ascomicetos/genética , Ascomicetos/patogenicidad , Ascomicetos/efectos de los fármacos , Caspofungina/farmacología , Pruebas de Sensibilidad Microbiana , Fluconazol/farmacología , Micosis/microbiología , Farmacorresistencia Fúngica Múltiple/genética , Farmacorresistencia Fúngica/genética
4.
Metab Eng ; 84: 117-127, 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38901555

RESUMEN

Effective utilization of glucose, xylose, and acetate, common carbon sources in lignocellulose hydrolysate, can boost biomanufacturing economics. However, carbon leaks into biomass biosynthesis pathways instead of the intended target product remain to be optimized. This study aimed to enhance α-carotene production by optimizing glucose, xylose, and acetate utilization in a high-efficiency Corynebacterium glutamicum cell factory. Heterologous xylose pathway expression in C. glutamicum resulted in strain m4, exhibiting a two-fold increase in α-carotene production from xylose compared to glucose. Xylose utilization was found to boost the biosynthesis of pyruvate and acetyl-CoA, essential precursors for carotenoid biosynthesis. Additionally, metabolic engineering including pck, pyc, ppc, and aceE deletion, completely disrupted the metabolic connection between glycolysis and the TCA cycle, further enhancing α-carotene production. This strategic intervention directed glucose and xylose primarily towards target chemical production, while acetate supplied essential metabolites for cell growth recovery. The engineered strain C. glutamicum m8 achieved 30 mg/g α-carotene, 67% higher than strain m4. In fed-batch fermentation, strain m8 produced 1802 mg/L of α-carotene, marking the highest titer reported to date in microbial fermentation. Moreover, it exhibited excellent performance in authentic lignocellulosic hydrolysate, producing 216 mg/L α-carotene, 1.45 times higher than the initial strain (m4). These labor-division strategies significantly contribute to the development of clean processes for producing various valuable chemicals from lignocellulosic resources.

5.
J Agric Food Chem ; 72(19): 10772-10780, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38703122

RESUMEN

Protoporphyrinogen IX oxidase (PPO, E.C. 1.3.3.4) plays a pivotal role in chlorophyll biosynthesis in plants, making it a prime target for herbicide development. In this study, we conducted an investigation aimed at discovering PPO-inhibiting herbicides. Through this endeavor, we successfully identified a series of novel compounds based on the pyridazinone scaffold. Following structural optimization and biological assessment, compound 10ae, known as ethyl 3-((6-fluoro-5-(6-oxo-4-(trifluoromethyl)pyridazin-1(6H)-yl)benzo[d]thiazol-2-yl)thio)propanoate, emerged as a standout performer. It exhibited robust activity against Nicotiana tabacum PPO (NtPPO) with an inhibition constant (Ki) value of 0.0338 µM. Concurrently, we employed molecular simulations to obtain further insight into the binding mechanism with NtPPO. Additionally, another compound, namely, ethyl 2-((6-fluoro-5-(5-methyl-6-oxo-4-(trifluoromethyl)pyridazin-1(6H)-yl)benzo[d]thiazol-2-yl)thio)propanoate (10bh), demonstrated broad-spectrum and highly effective herbicidal properties against all six tested weeds (Leaf mustard, Chickweed, Chenopodium serotinum, Alopecurus aequalis, Poa annua, and Polypogon fugax) at the dosage of 150 g a.i./ha through postemergence application in a greenhouse. This work identified a novel lead compound (10bh) that showed good activity in vitro and excellent herbicidal activity in vivo and had promising prospects as a new PPO-inhibiting herbicide lead.


Asunto(s)
Diseño de Fármacos , Inhibidores Enzimáticos , Herbicidas , Nicotiana , Proteínas de Plantas , Protoporfirinógeno-Oxidasa , Piridazinas , Protoporfirinógeno-Oxidasa/antagonistas & inhibidores , Protoporfirinógeno-Oxidasa/metabolismo , Protoporfirinógeno-Oxidasa/química , Protoporfirinógeno-Oxidasa/genética , Piridazinas/química , Piridazinas/farmacología , Herbicidas/farmacología , Herbicidas/química , Herbicidas/síntesis química , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/síntesis química , Relación Estructura-Actividad , Nicotiana/metabolismo , Nicotiana/enzimología , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Proteínas de Plantas/antagonistas & inhibidores , Proteínas de Plantas/genética , Simulación del Acoplamiento Molecular , Estructura Molecular , Malezas/efectos de los fármacos , Malezas/enzimología , Cinética
6.
Biotechnol Adv ; 73: 108372, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38714276

RESUMEN

Anaerobic digestion (AD) is an effective and applicable technology for treating organic wastes to recover bioenergy, but it is limited by various drawbacks, such as long start-up time for establishing a stable process, the toxicity of accumulated volatile fatty acids and ammonia nitrogen to methanogens resulting in extremely low biogas productivities, and a large amount of impurities in biogas for upgrading thereafter with high cost. Microbial electrolysis cell (MEC) is a device developed for electrosynthesis from organic wastes by electroactive microorganisms, but MEC alone is not practical for production at large scales. When AD is integrated with MEC, not only can biogas production be enhanced substantially, but also upgrading of the biogas product performed in situ. In this critical review, the state-of-the-art progress in developing AD-MEC systems is commented, and fundamentals underlying methanogenesis and bioelectrochemical reactions, technological innovations with electrode materials and configurations, designs and applications of AD-MEC systems, and strategies for their enhancement, such as driving the MEC device by electricity that is generated by burning the biogas to improve their energy efficiencies, are specifically addressed. Moreover, perspectives and challenges for the scale up of AD-MEC systems are highlighted for in-depth studies in the future to further improve their performance.


Asunto(s)
Fuentes de Energía Bioeléctrica , Biocombustibles , Electrólisis , Anaerobiosis , Fuentes de Energía Bioeléctrica/microbiología , Reactores Biológicos , Metano/metabolismo
7.
Inorg Chem ; 63(21): 9823-9830, 2024 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-38757599

RESUMEN

It can provide ideas for the use of uranium elements in the treatment of spent fuel from nuclear wastewater to explore the application potential of uranium element. Thus, it is necessary to research the structure and properties of a novel uranyl coordination polymer (CP) for uranium recovery and reuse. Herein, we designed and prepared a new uranyl CP U-CMNDI based on UO22+ and H2CMNDI (H2CMNDI = N, N'-bis(carboxymethyl)-1,4,5,8-naphthalenediimide). Structural analysis shows that two uranyl ions are connected by two parallel deprotonated CMNDI ligands to form a discrete uranyl dimer structure. U-CMNDI can act as a potential stimulus-responsive halide ion sensor by a fluorescence "turn on" response in water. The limit of detection for fluoride (F-), bromide (Br-), iodide (I-), and chloride (Cl-) is 5.00, 5.32, 5.49, and 5.73 µM, respectively. The fluorescence "turn on" behavior is based on the photoinduced electron transfer (PET) mechanism between halide ions and electron-deficient NDI cores. In addition, U-CMNDI demonstrates a color response to ultraviolet light, exhibiting reversible photochromic behavior with a notable color change. The color change mechanism can contribute to the PET process and the radical process.

8.
Bioresour Technol ; 402: 130774, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38701983

RESUMEN

Formate as an ideal mediator between the physicochemical and biological realms can be obtained from electrochemical reduction of CO2 and used to produce bio-chemicals. Yet, limitations arise when employing natural formate-utilizing microorganisms due to restricted product range and low biomass yield. This study presents a breakthrough: engineered Corynebacterium glutamicum strains (L2-L4) through modular engineering. L2 incorporates the formate-tetrahydrofolate cycle and reverse glycine cleavage pathway, L3 enhances NAD(P)H regeneration, and L4 reinforces metabolic flux. Metabolic modeling elucidates C1 assimilation, guiding strain optimization for co-fermentation of formate and glucose. Strain L4 achieves an OD600 of 0.5 and produces 0.6 g/L succinic acid. 13C-labeled formate confirms C1 assimilation, and further laboratory evolution yields 1.3 g/L succinic acid. This study showcases a successful model for biologically assimilating formate in C. glutamicum that could be applied in C1-based biotechnological production, ultimately forming a formate-based bioeconomy.


Asunto(s)
Biomasa , Corynebacterium glutamicum , Formiatos , Ingeniería Metabólica , Ácido Succínico , Corynebacterium glutamicum/metabolismo , Formiatos/metabolismo , Ingeniería Metabólica/métodos , Ácido Succínico/metabolismo , Fermentación , Modelos Biológicos , Glucosa/metabolismo
9.
Hypertens Res ; 47(7): 1952-1961, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38632456

RESUMEN

Data on the prognosis of clinically undiagnosed hypertensive patients who are aldosterone-to-renin ratio (ARR) positive are still scarce. Therefore, we investigated the clinical characteristics of clinically undiagnosed hypertensive patients who were ARR-positive and the influence of their different treatments on the occurrence and development of complications. A total of 285 hypertensive patients data with ARR ≥ 3.8 in the Second People's Hospital of Huai'an from January 2019 to December 2021 were collected, and 135 undiagnosed hypertensive patients were ultimately included in the analysis. According to their treatment strategy in various clinical departments, 135 patients were divided into the operation, spironolactone and control groups. Then, the clinical characteristics and the occurrence and development of complications in the three groups were compared. The results suggested that: (1) Only 34 (11.9%) of 285 hypertensive patients with ARR ≥ 3.8 were clearly diagnosed with Primary aldosteronism (PA) through functional tests, and the blood pressure (BP) compliance rate was only 50.30% during follow-up. (2) Based on exclusion criteria, 135 undiagnosed hypertensive patients were eventually included in the analysis. Patients in the surgery group had lower blood potassium levels and higher aldosterone levels than those in the other two groups, and their risk of new cerebrovascular complications was lower than that of the patients in the spironolactone group. (3) The risk of new cerebrovascular complications in the spironolactone group was 9.520 times higher than that of the control group, and this risk mainly occurred in patients with ARR values of 3.8-5.7. On the whole, surgery remains a good option for hypertensive patients with severe hyperaldosteronism and hypokalemia and those unable to undergo confirmatory tests; however, spironolactone therapy in patients with clinically undiagnosed hypertension, especially those with 3.8 ≤ ARR < 5.7, confered a higher risk of new cerebrovascular complications.


Asunto(s)
Aldosterona , Hiperaldosteronismo , Hipertensión , Renina , Espironolactona , Humanos , Hipertensión/tratamiento farmacológico , Hipertensión/complicaciones , Masculino , Femenino , Persona de Mediana Edad , Aldosterona/sangre , Espironolactona/uso terapéutico , Renina/sangre , Hiperaldosteronismo/complicaciones , Hiperaldosteronismo/terapia , Hiperaldosteronismo/tratamiento farmacológico , Anciano , Adulto , Enfermedades Cardiovasculares/etiología , Antagonistas de Receptores de Mineralocorticoides/uso terapéutico , Presión Sanguínea
10.
BMC Biol ; 22(1): 85, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38627785

RESUMEN

BACKGROUND: Inadequate DNA damage repair promotes aberrant differentiation of mammary epithelial cells. Mammary luminal cell fate is mainly determined by a few transcription factors including GATA3. We previously reported that GATA3 functions downstream of BRCA1 to suppress aberrant differentiation in breast cancer. How GATA3 impacts DNA damage repair preventing aberrant cell differentiation in breast cancer remains elusive. We previously demonstrated that loss of p18, a cell cycle inhibitor, in mice induces luminal-type mammary tumors, whereas depletion of either Brca1 or Gata3 in p18 null mice leads to basal-like breast cancers (BLBCs) with activation of epithelial-mesenchymal transition (EMT). We took advantage of these mutant mice to examine the role of Gata3 as well as the interaction of Gata3 and Brca1 in DNA damage repair in mammary tumorigenesis. RESULTS: Depletion of Gata3, like that of Brca1, promoted DNA damage accumulation in breast cancer cells in vitro and in basal-like breast cancers in vivo. Reconstitution of Gata3 improved DNA damage repair in Brca1-deficient mammary tumorigenesis. Overexpression of GATA3 promoted homologous recombination (HR)-mediated DNA damage repair and restored HR efficiency of BRCA1-deficient cells. Depletion of Gata3 sensitized tumor cells to PARP inhibitor (PARPi), and reconstitution of Gata3 enhanced resistance of Brca1-deficient tumor cells to PARP inhibitor. CONCLUSIONS: These results demonstrate that Gata3 functions downstream of BRCA1 to promote DNA damage repair and suppress dedifferentiation in mammary tumorigenesis and progression. Our findings suggest that PARP inhibitors are effective for the treatment of GATA3-deficient BLBCs.


Asunto(s)
Neoplasias Mamarias Animales , Inhibidores de Poli(ADP-Ribosa) Polimerasas , Animales , Ratones , Línea Celular Tumoral , Transformación Celular Neoplásica/genética , Daño del ADN , Reparación del ADN , Neoplasias Mamarias Animales/genética , Neoplasias Mamarias Animales/patología , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología
11.
Inorg Chem ; 63(16): 7233-7240, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38588385

RESUMEN

Reaction of tetraphenyl-21-thiaporphyrin (HSTPP) with cobalt salt yields a pentacoordinated high-spin 3/2 [CoIICl(STTP)] (1). Through ion exchange, a roughly square-planar-geometry low-spin 1/2 CoIISTTP(BArF24) (2) complex was isolated. These two paramagnetic precursors were examined by single X-ray diffraction, nuclear magnetic resonance, electron paramagnetic resonance, superconducting quantum interference device, and density functional theory calculations. These two allowed the development of one electron reduction and oxidation to give [CoI(STTP)] (3), [CoIII(STTP)Cl(CH3CN)](BF4) (4), and [CoIII(STTP)Cl2] (5). The products of the chemical redox reactions were isolated and fully characterized. In addition, the reactivity of [CoIICl(STTP)] (1) was examined by azide (N3), cyanate (OCN), and thiocyanate (SCN) and featured a preferential N-coordination to the cobalt metal.

12.
Nat Commun ; 15(1): 2894, 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38570494

RESUMEN

Steroidal glycoalkaloids (SGAs) are major plant defense metabolites against pests, while they are considered poisonous in food. The genetic basis that guides negative selection of SGAs production during tomato domestication remains poorly understood. Here, we identify a distal enhancer, GAME Enhancer 1 (GE1), as the key regulator of SGAs metabolism in tomato. GE1 recruits MYC2-GAME9 transcriptional complex to regulate the expression of GAME cluster genes via the formation of chromatin loops located in the neighboring DNA region. A naturally occurring GE176 allelic variant is found to be more active in stimulating GAME expression. We show that the weaker GE1 allele has been the main driver for selecting reduced SGAs levels during tomato domestication. Unravelling the "TFs-Enhancer-Promoter" regulatory mechanism operating in SGAs metabolism opens unprecedented prospects for SGAs manipulation in Solanaceae via precision breeding strategies.


Asunto(s)
Solanaceae , Solanum lycopersicum , Solanum lycopersicum/genética , Domesticación , Fitomejoramiento , Esteroides
14.
Chem Commun (Camb) ; 60(33): 4423-4426, 2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38523593

RESUMEN

A pair of isomeric Py-BT-COFs with the same composition, but slightly different atomic arrangements, were designed and synthesized. The minute structural variations of the Py-BT-COF isomers generated significantly different redox and photophysical properties and correspondingly led to different photocatalytic manifestations in H2 evolution and rhodamine B degradation.

15.
Artículo en Inglés | MEDLINE | ID: mdl-38536076

RESUMEN

Three yeast strains belonging to the ascomycetous yeast genus Pichia were isolated from two soil samples from Yunnan and Guizhou provinces and a marine water sample from Liaoning province, PR China. Phylogenetic analyses based on the sequences of the D1/D2 domains of the large subunit(LSU) rRNA gene and the internal transcribed spacer (ITS) region indicate that these three strains, together with 12 additional strains isolated from various substrates collected in different regions or countries of the world, represent a novel species of the genus Pichia, for which the name Pichia kurtzmaniana sp. nov. (holotype: strain CGMCC 2.7213) is proposed. The novel species differs from its close relatives Candida californica by eight (1.5 %) and 26 (11.1 %) mismatches in the D1/D2 domains and the ITS region, respectively; and from Pichia chibodasensis by 11 (2.1 %) and 20 (8.7 %) mismatches in the D1/D2 domains and the ITS region, respectively. In addition, eight Candida species which belong to the Pichia clade are transferred to the genus Pichia, resulting in the proposal of the following new combinations: Pichia cabralensis comb. nov., Pichia californica comb. nov., Pichia ethanolica comb. nov., Pichia inconspicua comb. nov., Pichia phayaonensis comb. nov., Pichia pseudolambica comb. nov., Pichia rugopelliculosa comb. nov., and Pichia thaimueangensis comb. nov.


Asunto(s)
Candida , Pichia , Técnicas de Tipificación Bacteriana , Composición de Base , China , ADN Bacteriano/genética , Ácidos Grasos/química , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
16.
Cancer Res ; 84(6): 855-871, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38486485

RESUMEN

Immune checkpoint inhibitors (ICI) transformed the treatment landscape of hepatocellular carcinoma (HCC). Unfortunately, patients with attenuated MHC-I expression remain refractory to ICIs, and druggable targets for upregulating MHC-I are limited. Here, we found that genetic or pharmacologic inhibition of fatty acid synthase (FASN) increased MHC-I levels in HCC cells, promoting antigen presentation and stimulating antigen-specific CD8+ T-cell cytotoxicity. Mechanistically, FASN inhibition reduced palmitoylation of MHC-I that led to its lysosomal degradation. The palmitoyltransferase DHHC3 directly bound MHC-I and negatively regulated MHC-I protein levels. In an orthotopic HCC mouse model, Fasn deficiency enhanced MHC-I levels and promoted cancer cell killing by tumor-infiltrating CD8+ T cells. Moreover, the combination of two different FASN inhibitors, orlistat and TVB-2640, with anti-PD-L1 antibody robustly suppressed tumor growth in vivo. Multiplex IHC of human HCC samples and bioinformatic analysis of The Cancer Genome Atlas data further illustrated that lower expression of FASN was correlated with a higher percentage of cytotoxic CD8+ T cells. The identification of FASN as a negative regulator of MHC-I provides the rationale for combining FASN inhibitors and immunotherapy for treating HCC. SIGNIFICANCE: Inhibition of FASN increases MHC-I protein levels by suppressing its palmitoylation and lysosomal degradation, which stimulates immune activity against hepatocellular carcinoma and enhances the efficacy of immune checkpoint inhibition.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Animales , Humanos , Ratones , Antígeno B7-H1/metabolismo , Carcinoma Hepatocelular/genética , Línea Celular , Acido Graso Sintasa Tipo I , Neoplasias Hepáticas/genética , Proteínas
17.
ACS Nano ; 18(12): 9100-9113, 2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38478044

RESUMEN

Reactive oxygen species (ROS) mediated tumor cell death is a powerful anticancer strategy. Cuproptosis is a copper-dependent and ROS-mediated prospective tumor therapy strategy. However, the complex tumor microenvironment (TME), low tumor specificity, poor therapy efficiency, and lack of imaging capability impair the therapy output of current cuproptosis drugs. Herein, we designed a dual-responsive two-dimensional metal-organic framework (2D MOF) nanotheranostic via a coordination self-assembly strategy using Au(III) tetra-(4-pyridyl) porphine (AuTPyP) as the ligand and copper ions (Cu2+) as nodes. The dual-stimulus combined with the protonation of the pyridyl group in AuTPyP and deep-penetration ultrasound (US) together triggered the controlled release in an acidic TME. The ultrathin structure (3.0 nm) of nanotheranostics promoted the release process. The released Cu2+ was reduced to Cu+ by depleting the overexpressed glutathione (GSH) in the tumor, which not only activated the Ferredoxin 1 (FDX1)-mediated cuproptosis but also catalyzed the overexpressed hydrogen peroxide (H2O2) in the tumor into reactive oxygen species via Fenton-like reaction. Simultaneously, the released AuTPyP could specifically bind with thioredoxin reductase and activate the redox imbalance of tumor cells. These together selectively induced significant mitochondrial vacuoles and prominent tumor cell death but did not damage the normal cells. The fluorescence and magnetic resonance imaging (MRI) results verified this nanotheranostic could target the HeLa tumor to greatly promote the self-enhanced effect of chemotherapy/cuproptosis and tumor inhibition efficiency. The work helped to elucidate the controlled assembly of multiresponsive nanotheranostics and the high-specificity ROS regulation for application in anticancer therapy.


Asunto(s)
Estructuras Metalorgánicas , Nanopartículas , Neoplasias , Humanos , Cobre , Estructuras Metalorgánicas/farmacología , Especies Reactivas de Oxígeno , Peróxido de Hidrógeno , Estudios Prospectivos , Glutatión , Concentración de Iones de Hidrógeno , Neoplasias/diagnóstico por imagen , Neoplasias/tratamiento farmacológico , Línea Celular Tumoral , Microambiente Tumoral
18.
Cell Commun Signal ; 22(1): 147, 2024 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-38388921

RESUMEN

BACKGROUND: Patients with Alzheimer's disease (AD) are often co-morbid with unprovoked seizures, making clinical diagnosis and management difficult. Although it has an important role in both AD and epilepsy, abnormal γ-aminobutyric acid (GABA)ergic transmission is recognized only as a compensative change for glutamatergic damage. Neuregulin 1 (NRG1)-ErbB4 signaling can promote GABA release and suppress epileptogenesis, but its effects on cognition in AD are still controversial. METHODS: Four-month-old APPswe/PS1dE9 mice (APP mice) were used as animal models in the early stage of AD in this study. Acute/chronic chemical-kindling epilepsy models were established with pentylenetetrazol. Electroencephalogram and Racine scores were performed to assess seizures. Behavioral tests were used to assess cognition and emotion. Electrophysiology, western blot and immunofluorescence were performed to detect the alterations in synapses, GABAergic system components and NRG1-ErbB4 signaling. Furthermore, NRG1 was administrated intracerebroventricularly into APP mice and then its antiepileptic and cognitive effects were evaluated. RESULTS: APP mice had increased susceptibility to epilepsy and resulting hippocampal synaptic damage and cognitive impairment. Electrophysiological analysis revealed decreased GABAergic transmission in the hippocampus. This abnormal GABAergic transmission involved a reduction in the number of parvalbumin interneurons (PV+ Ins) and decreased levels of GABA synthesis and transport. We also found impaired NRG1-ErbB4 signaling which mediated by PV+ Ins loss. And NRG1 administration could effectively reduce seizures and improve cognition in four-month-old APP mice. CONCLUSION: Our results indicated that abnormal GABAergic transmission mediated hippocampal hyperexcitability, further excitation/inhibition imbalance, and promoted epileptogenesis in the early stage of AD. Appropriate NRG1 administration could down-regulate seizure susceptibility and rescue cognitive function. Our study provided a potential direction for intervening in the co-morbidity of AD and epilepsy.


Asunto(s)
Enfermedad de Alzheimer , Epilepsia , Humanos , Ratones , Animales , Lactante , Receptor ErbB-4/metabolismo , Enfermedad de Alzheimer/complicaciones , Hipocampo/metabolismo , Ácido gamma-Aminobutírico , Convulsiones , Neurregulina-1/metabolismo
19.
Artículo en Inglés | MEDLINE | ID: mdl-38415711

RESUMEN

A yeast strain (CGMCC 2.6937T) belonging to the ascomycetous yeast genus Saturnispora was recently isolated from soil collected in Xinghuacun, Shanxi Province, PR China. The strain produces one or two ellipsoid or spherical ascospores in asci formed by the conjugation between a cell and its bud. Phylogenetic analyses of the internal transcribed spacer (ITS) region and the D1/D2 domain of the large subunit rRNA gene suggest that this strain is conspecific with strains NYNU 14639 isolated from rotten wood collected in Funiu Mountain, Henan province and ES13S05 from soil collected in Nantou County, Taiwan. The CGMCC 2.6937T group is most closely related to Saturnispora dispora and Saturnispora zaruensis. However, strain CGMCC 2.6937T differs from S. dispora by 17 (3.2 %, 13 substitutions and four gaps) and 77 (18.8 %, 52 substitutions and 25 gaps) mismatches, and from S. zaruensis by 15 (2.9 %, 12 substitutions and three gaps) and 64 (15.6 %, 44 substitutions and 20 gaps) mismatches, in the D1/D2 domain and ITS region, respectively. The results suggest that the CGMCC 2.6937T group represents an undescribed species in the genus Saturnispora, for which the name Saturnispora sinensis sp. nov. is proposed. The holotype strain is CGMCC 2.6937T.


Asunto(s)
Ascomicetos , Filogenia , Microbiología del Suelo , Madera , Ascomicetos/clasificación , Ascomicetos/genética , Composición de Base , Análisis de Secuencia de ADN , Madera/microbiología , Técnicas de Tipificación Micológica
20.
Nat Metab ; 6(3): 531-549, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38409606

RESUMEN

Ageing increases susceptibility to neurodegenerative disorders, such as Alzheimer's disease (AD). Serum levels of sclerostin, an osteocyte-derived Wnt-ß-catenin signalling antagonist, increase with age and inhibit osteoblastogenesis. As Wnt-ß-catenin signalling acts as a protective mechanism for memory, we hypothesize that osteocyte-derived sclerostin can impact cognitive function under pathological conditions. Here we show that osteocyte-derived sclerostin can cross the blood-brain barrier of old mice, where it can dysregulate Wnt-ß-catenin signalling. Gain-of-function and loss-of-function experiments show that abnormally elevated osteocyte-derived sclerostin impairs synaptic plasticity and memory in old mice of both sexes. Mechanistically, sclerostin increases amyloid ß (Aß) production through ß-catenin-ß-secretase 1 (BACE1) signalling, indicating a functional role for sclerostin in AD. Accordingly, high sclerostin levels in patients with AD of both sexes are associated with severe cognitive impairment, which is in line with the acceleration of Αß production in an AD mouse model with bone-specific overexpression of sclerostin. Thus, we demonstrate osteocyte-derived sclerostin-mediated bone-brain crosstalk, which could serve as a target for developing therapeutic interventions against AD.


Asunto(s)
Enfermedad de Alzheimer , Humanos , Masculino , Femenino , Ratones , Animales , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/uso terapéutico , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Secretasas de la Proteína Precursora del Amiloide/uso terapéutico , Osteocitos/metabolismo , Osteocitos/patología , beta Catenina/metabolismo , beta Catenina/uso terapéutico , Ácido Aspártico Endopeptidasas/metabolismo , Ácido Aspártico Endopeptidasas/uso terapéutico , Vía de Señalización Wnt , Cognición , Envejecimiento
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...