Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.147
Filtrar
Más filtros

Intervalo de año de publicación
1.
Cell ; 183(2): 490-502.e18, 2020 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-33002410

RESUMEN

The non-receptor protein tyrosine phosphatase (PTP) SHP2, encoded by PTPN11, plays an essential role in RAS-mitogen-activated protein kinase (MAPK) signaling during normal development. It has been perplexing as to why both enzymatically activating and inactivating mutations in PTPN11 result in human developmental disorders with overlapping clinical manifestations. Here, we uncover a common liquid-liquid phase separation (LLPS) behavior shared by these disease-associated SHP2 mutants. SHP2 LLPS is mediated by the conserved well-folded PTP domain through multivalent electrostatic interactions and regulated by an intrinsic autoinhibitory mechanism through conformational changes. SHP2 allosteric inhibitors can attenuate LLPS of SHP2 mutants, which boosts SHP2 PTP activity. Moreover, disease-associated SHP2 mutants can recruit and activate wild-type (WT) SHP2 in LLPS to promote MAPK activation. These results not only suggest that LLPS serves as a gain-of-function mechanism involved in the pathogenesis of SHP2-associated human diseases but also provide evidence that PTP may be regulated by LLPS that can be therapeutically targeted.


Asunto(s)
Proteínas Quinasas Activadas por Mitógenos/metabolismo , Proteína Tirosina Fosfatasa no Receptora Tipo 11/metabolismo , Células A549 , Animales , Niño , Preescolar , Femenino , Mutación con Ganancia de Función/genética , Células HEK293 , Células Endoteliales de la Vena Umbilical Humana , Humanos , Sistema de Señalización de MAP Quinasas/fisiología , Masculino , Ratones , Células Madre Embrionarias de Ratones , Mutación/genética , Proteína Tirosina Fosfatasa no Receptora Tipo 11/genética , Transducción de Señal , Dominios Homologos src/genética
2.
Cell ; 160(1-2): 88-104, 2015 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-25594176

RESUMEN

The primary task of white adipose tissue (WAT) is the storage of lipids. However, "beige" adipocytes also exist in WAT. Beige adipocytes burn fat and dissipate the energy as heat, but their abundance is diminished in obesity. Stimulating beige adipocyte development, or WAT browning, increases energy expenditure and holds potential for combating metabolic disease and obesity. Here, we report that insulin and leptin act together on hypothalamic neurons to promote WAT browning and weight loss. Deletion of the phosphatases PTP1B and TCPTP enhanced insulin and leptin signaling in proopiomelanocortin neurons and prevented diet-induced obesity by increasing WAT browning and energy expenditure. The coinfusion of insulin plus leptin into the CNS or the activation of proopiomelanocortin neurons also increased WAT browning and decreased adiposity. Our findings identify a homeostatic mechanism for coordinating the status of energy stores, as relayed by insulin and leptin, with the central control of WAT browning.


Asunto(s)
Tejido Adiposo Pardo/metabolismo , Tejido Adiposo Blanco/metabolismo , Insulina/metabolismo , Leptina/metabolismo , Proopiomelanocortina/metabolismo , Adiposidad , Animales , Regulación de la Temperatura Corporal , Ratones Endogámicos C57BL , Ratones Noqueados , Neuronas/metabolismo , Obesidad/metabolismo , Proteína Tirosina Fosfatasa no Receptora Tipo 1/metabolismo , Proteína Tirosina Fosfatasa no Receptora Tipo 2/metabolismo
3.
J Neurosci ; 44(18)2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38508714

RESUMEN

Drugs of abuse induce neuroadaptations, including synaptic plasticity, that are critical for transition to addiction, and genes and pathways that regulate these neuroadaptations are potential therapeutic targets. Tropomodulin 2 (Tmod2) is an actin-regulating gene that plays an important role in synapse maturation and dendritic arborization and has been implicated in substance abuse and intellectual disability in humans. Here, we mine the KOMP2 data and find that Tmod2 knock-out mice show emotionality phenotypes that are predictive of addiction vulnerability. Detailed addiction phenotyping shows that Tmod2 deletion does not affect the acute locomotor response to cocaine administration. However, sensitized locomotor responses are highly attenuated in these knock-outs, indicating perturbed drug-induced plasticity. In addition, Tmod2 mutant animals do not self-administer cocaine indicating lack of hedonic responses to cocaine. Whole-brain MR imaging shows differences in brain volume across multiple regions, although transcriptomic experiments did not reveal perturbations in gene coexpression networks. Detailed electrophysiological characterization of Tmod2 KO neurons showed increased spontaneous firing rate of early postnatal and adult cortical and striatal neurons. Cocaine-induced synaptic plasticity that is critical for sensitization is either missing or reciprocal in Tmod2 KO nucleus accumbens shell medium spiny neurons, providing a mechanistic explanation of the cocaine response phenotypes. Combined, these data, collected from both males and females, provide compelling evidence that Tmod2 is a major regulator of plasticity in the mesolimbic system and regulates the reinforcing and addictive properties of cocaine.


Asunto(s)
Cocaína , Cuerpo Estriado , Ratones Noqueados , Plasticidad Neuronal , Animales , Cocaína/farmacología , Plasticidad Neuronal/efectos de los fármacos , Plasticidad Neuronal/fisiología , Ratones , Masculino , Cuerpo Estriado/efectos de los fármacos , Cuerpo Estriado/metabolismo , Ratones Endogámicos C57BL , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/fisiología , Femenino , Trastornos Relacionados con Cocaína/fisiopatología , Trastornos Relacionados con Cocaína/genética , Proteínas de Microfilamentos/metabolismo , Proteínas de Microfilamentos/genética , Excitabilidad Cortical/efectos de los fármacos , Inhibidores de Captación de Dopamina/farmacología , Inhibidores de Captación de Dopamina/administración & dosificación
4.
Blood ; 141(3): 244-259, 2023 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-36206490

RESUMEN

Acute myeloid leukemia (AML) is an aggressive blood cancer with poor prognosis. FMS-like tyrosine kinase receptor-3 (FLT3) is one of the major oncogenic receptor tyrosine kinases aberrantly activated in AML. Although protein tyrosine phosphatase PRL2 is highly expressed in some subtypes of AML compared with normal human hematopoietic stem and progenitor cells, the mechanisms by which PRL2 promotes leukemogenesis are largely unknown. We discovered that genetic and pharmacological inhibition of PRL2 significantly reduce the burden of FLT3-internal tandem duplications-driven leukemia and extend the survival of leukemic mice. Furthermore, we found that PRL2 enhances oncogenic FLT3 signaling in leukemia cells, promoting their proliferation and survival. Mechanistically, PRL2 dephosphorylates the E3 ubiquitin ligase CBL at tyrosine 371 and attenuates CBL-mediated ubiquitination and degradation of FLT3, leading to enhanced FLT3 signaling in leukemia cells. Thus, our study reveals that PRL2 enhances oncogenic FLT3 signaling in leukemia cells through dephosphorylation of CBL and will likely establish PRL2 as a novel druggable target for AML.


Asunto(s)
Leucemia Mieloide Aguda , Ubiquitina-Proteína Ligasas , Humanos , Animales , Ratones , Ubiquitina-Proteína Ligasas/metabolismo , Monoéster Fosfórico Hidrolasas/genética , Transducción de Señal/genética , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Proteínas Proto-Oncogénicas c-cbl/genética , Proteínas Proto-Oncogénicas c-cbl/metabolismo , Tirosina Quinasa 3 Similar a fms/genética , Tirosina Quinasa 3 Similar a fms/metabolismo , Mutación
5.
Subcell Biochem ; 104: 485-501, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38963497

RESUMEN

Valosin-containing protein (VCP), also known as p97, is an evolutionarily conserved AAA+ ATPase essential for cellular homeostasis. Cooperating with different sets of cofactors, VCP is involved in multiple cellular processes through either the ubiquitin-proteasome system (UPS) or the autophagy/lysosomal route. Pathogenic mutations frequently found at the interface between the NTD domain and D1 ATPase domain have been shown to cause malfunction of VCP, leading to degenerative disorders including the inclusion body myopathy associated with Paget disease of bone and frontotemporal dementia (IBMPFD), amyotrophic lateral sclerosis (ALS), and cancers. Therefore, VCP has been considered as a potential therapeutic target for neurodegeneration and cancer. Most of previous studies found VCP predominantly exists and functions as a hexamer, which unfolds and extracts ubiquitinated substrates from protein complexes for degradation. However, recent studies have characterized a new VCP dodecameric state and revealed a controlling mechanism of VCP oligomeric states mediated by the D2 domain nucleotide occupancy. Here, we summarize our recent knowledge on VCP oligomerization, regulation, and potential implications of VCP in cellular function and pathogenic progression.


Asunto(s)
Proteína que Contiene Valosina , Proteína que Contiene Valosina/metabolismo , Proteína que Contiene Valosina/genética , Proteína que Contiene Valosina/química , Humanos , Multimerización de Proteína , Animales , Mutación , Demencia Frontotemporal/genética , Demencia Frontotemporal/metabolismo , Adenosina Trifosfatasas/metabolismo , Adenosina Trifosfatasas/genética , Adenosina Trifosfatasas/química , Osteítis Deformante/genética , Osteítis Deformante/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/química , Miositis por Cuerpos de Inclusión/genética , Miositis por Cuerpos de Inclusión/metabolismo , Distrofia Muscular de Cinturas
6.
Proc Natl Acad Sci U S A ; 119(12): e2114583119, 2022 03 22.
Artículo en Inglés | MEDLINE | ID: mdl-35290117

RESUMEN

Communication between interacting organisms via bioactive molecules is widespread in nature and plays key roles in diverse biological processes. Small RNAs (sRNAs) can travel between host plants and filamentous pathogens to trigger transkingdom RNA interference (RNAi) in recipient cells and modulate plant defense and pathogen virulence. However, how fungal pathogens counteract transkingdom antifungal RNAi has rarely been reported. Here we show that a secretory protein VdSSR1 (secretory silencing repressor 1) from Verticillium dahliae, a soil-borne phytopathogenic fungus that causes wilt diseases in a wide range of plant hosts, is required for fungal virulence in plants. VdSSR1 can translocate to plant nucleus and serve as a general suppressor of sRNA nucleocytoplasmic shuttling. We further reveal that VdSSR1 sequesters ALY family proteins, adaptors of the TREX complex, to interfere with nuclear export of the AGO1­microRNA (AGO1­miRNA) complex, leading to a great attenuation in cytoplasmic AGO1 protein and sRNA levels. With this mechanism, V. dahliae can suppress the accumulation of mobile plant miRNAs in fungal cells and succedent transkingdom silencing of virulence genes, thereby increasing its virulence in plants. Our findings reveal a mechanism by which phytopathogenic fungi antagonize antifungal RNAi-dependent plant immunity and expand the understanding on the complex interaction between host and filamentous pathogens.


Asunto(s)
MicroARNs , Verticillium , Transporte Activo de Núcleo Celular , Antifúngicos , MicroARNs/genética , MicroARNs/metabolismo , Enfermedades de las Plantas/microbiología , Plantas/genética , ARN de Planta , Verticillium/metabolismo
7.
Proc Natl Acad Sci U S A ; 119(26): e2121513119, 2022 06 28.
Artículo en Inglés | MEDLINE | ID: mdl-35737832

RESUMEN

Both chronic obstructive pulmonary disease (COPD) and asthma are severe respiratory diseases. Bitter receptor-mediated bronchodilation is a potential therapy for asthma, but the mechanism underlying the agonistic relaxation of airway smooth muscle (ASM) is not well defined. By exploring the ASM relaxation mechanism of bitter substances, we observed that pretreatment with the bitter substances nearly abolished the methacholine (MCh)-induced increase in the ASM cell (ASMC) calcium concentration, thereby suppressing the calcium-induced contraction release. The ASM relaxation was significantly inhibited by simultaneous deletion of three Gαt proteins, suggesting an interaction between Tas2R and AChR signaling cascades in the relaxation process. Biochemically, the Gαt released by Tas2R activation complexes with AChR and blocks the Gαq cycling of AChR signal transduction. More importantly, a bitter substance, kudinoside A, not only attenuates airway constriction but also significantly inhibits pulmonary inflammation and tissue remodeling in COPD rats, indicating its modulation of additional Gαq-associated pathological processes. Thus, our results suggest that Tas2R activation may be an ideal strategy for halting multiple pathological processes of COPD.


Asunto(s)
Asma , Músculo Liso , Enfermedad Pulmonar Obstructiva Crónica , Receptores Acoplados a Proteínas G , Activación Transcripcional , Animales , Asma/genética , Asma/metabolismo , Asma/fisiopatología , Broncodilatadores/farmacología , Calcio/metabolismo , Músculo Liso/efectos de los fármacos , Músculo Liso/metabolismo , Miocitos del Músculo Liso/efectos de los fármacos , Miocitos del Músculo Liso/metabolismo , Enfermedad Pulmonar Obstructiva Crónica/genética , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Ratas , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Transducción de Señal
8.
Nano Lett ; 24(9): 2765-2772, 2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38393855

RESUMEN

Alloying lanthanide ions (Yb3+) into perovskite quantum dots (Yb3+:CsPb(Cl1-xBrx)3) is an effective method to achieve efficient near-infrared (NIR) luminescence (>950 nm). Increasing the Yb3+ alloying ratio in the perovskite matrix enhances the luminescence intensity of Yb3+ emission at 990 nm. However, high Yb3+ alloying (>15%) results in vacancy-induced inferior material stability. In this work, we developed a polarity-mediated antisolvent manipulation strategy to resolve the incompatibility between a high Yb3+ alloying ratio and inferior stability of Yb3+:CsPb(Cl1-xBrx)3. Precise control of solution polarity enables increased uniformity of the perovskite matrix with fewer trap densities. Employing this strategy, we obtain Yb3+:CsPb(Cl1-xBrx)3 with the highest Yb3+ alloying ratio of 30.2% and a 2-fold higher electroluminescence intensity at 990 nm. We lever the engineered Yb3+:CsPb(Cl1-xBrx)3 to fabricate NIR-LEDs, achieving a peak external quantum efficiency (EQE) of 8.5% at 990 nm: this represents the highest among perovskite NIR-LEDs with an emission wavelength above 950 nm.

9.
Nano Lett ; 24(21): 6344-6352, 2024 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-38687224

RESUMEN

Anisotropic two-dimensional materials present a diverse range of physical characteristics, making them well-suited for applications in photonics and optoelectronics. While mechanical properties play a crucial role in determining the reliability and efficacy of 2D material-based devices, the fracture behavior of anisotropic 2D crystals remains relatively unexplored. Toward this end, we herein present the first measurement of the anisotropic fracture toughness of 2D Ta2NiSe5 by microelectromechanical system-based tensile tests. Our findings reveal a significant in-plane anisotropic ratio (∼3.0), accounting for crystal orientation-dependent crack paths. As the thickness increases, we observe an intriguing intraplanar-to-interplanar transition of fracture along the a-axis, manifesting as stepwise crack features attributed to interlayer slippage. In contrast, ruptures along the c-axis surprisingly exhibit persistent straightness and smoothness regardless of thickness, owing to the robust interlayer shear resistance. Our work affords a promising avenue for the construction of future electronics based on nanoribbons with atomically sharp edges.

10.
J Biol Chem ; 299(12): 105481, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38041932

RESUMEN

Singlet oxygen (1O2) has a very short half-life of 10-5 s; however, it is a strong oxidant that causes growth arrest and necrotic lesions on plants. Its signaling pathway remains largely unknown. The Arabidopsis flu (fluorescent) mutant accumulates a high level of 1O2 and shows drastic changes in nuclear gene expression. Only two plastid proteins, EX1 (executer 1) and EX2 (executer 2), have been identified in the singlet oxygen signaling. Here, we found that the transcription factor abscisic acid insensitive 4 (ABI4) binds the promoters of genes responsive to 1O2-signals. Inactivation of the ABI4 protein in the flu/abi4 double mutant was sufficient to compromise the changes of almost all 1O2-responsive-genes and rescued the lethal phenotype of flu grown under light/dark cycles, similar to the flu/ex1/ex2 triple mutant. In addition to cell death, we reported for the first time that 1O2 also induces cell wall thickening and stomatal development defect. Contrastingly, no apparent growth arrest was observed for the flu mutant under normal light/dim light cycles, but the cell wall thickening (doubled) and stomatal density reduction (by two-thirds) still occurred. These results offer a new idea for breeding stress tolerant plants.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Ácido Abscísico/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Pared Celular/metabolismo , Regulación de la Expresión Génica de las Plantas , Luz , Oxígeno Singlete/metabolismo , Transcriptoma , Estomas de Plantas/metabolismo
11.
J Am Chem Soc ; 146(12): 8425-8434, 2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38488481

RESUMEN

The precise design of catalytic metal centers with multiple chemical states to facilitate sophisticated reactions involving multimolecular activation is highly desirable but challenging. Herein, we report an ordered macroporous catalyst with heterovalent metal pair (HMP) sites comprising CuII-CuI on the basis of a microporous metal-organic framework (MOF) system. This macroporous HMP catalyst with proximity heterovalent dual copper sites, whose distance is controlled to ∼2.6 Å, on macropore surface exhibits a co-activation behavior of ethanol at CuII and alkyne at CuI, and avoids microporous restriction, thereby promoting additive-free alkyne hydroboration reaction. The desired yield enhances dramatically compared with the pristine MOF and ordered macroporous MOF both with solely isovalent CuII-CuII sites. Density functional theory calculations reveal that the Cu-HMP sites can stabilize the Bpin-CuII-CuI-alkyne intermediate and facilitate C-B bond formation, resulting in a smooth alkyne hydroboration process. This work provides new perspectives to design multimolecular activation catalysts for sophisticated matter transformations.

12.
EMBO J ; 39(2): e103637, 2020 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-31803974

RESUMEN

Although adoptive T-cell therapy has shown remarkable clinical efficacy in haematological malignancies, its success in combating solid tumours has been limited. Here, we report that PTPN2 deletion in T cells enhances cancer immunosurveillance and the efficacy of adoptively transferred tumour-specific T cells. T-cell-specific PTPN2 deficiency prevented tumours forming in aged mice heterozygous for the tumour suppressor p53. Adoptive transfer of PTPN2-deficient CD8+ T cells markedly repressed tumour formation in mice bearing mammary tumours. Moreover, PTPN2 deletion in T cells expressing a chimeric antigen receptor (CAR) specific for the oncoprotein HER-2 increased the activation of the Src family kinase LCK and cytokine-induced STAT-5 signalling, thereby enhancing both CAR T-cell activation and homing to CXCL9/10-expressing tumours to eradicate HER-2+ mammary tumours in vivo. Our findings define PTPN2 as a target for bolstering T-cell-mediated anti-tumour immunity and CAR T-cell therapy against solid tumours.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Inmunoterapia Adoptiva/métodos , Activación de Linfocitos/inmunología , Neoplasias/terapia , Proteína Tirosina Fosfatasa no Receptora Tipo 2/fisiología , Receptor ErbB-2/fisiología , Receptores de Antígenos de Linfocitos T/inmunología , Traslado Adoptivo , Animales , Presentación de Antígeno/inmunología , Femenino , Humanos , Masculino , Ratones , Ratones Noqueados , Ratones Transgénicos , Neoplasias/genética , Neoplasias/inmunología , Transducción de Señal
13.
Small ; : e2400410, 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38721986

RESUMEN

The construction of defective sites is one of the effective strategies to create high-activity Metal-Organic frameworks (MOFs) catalysts. However, traditional synthesis methods usually suffer from cumbersome synthesis steps and disordered defect structures. Herein, a cluster-cluster co-nucleation (CCCN) strategy is presented that involves the in situ introduction of size-matched functional polyoxometalates (H6P2W18O62, {P2W18}) to intervene the nucleation process of cluster-based MOFs (UiO-66), achieving one-step inducement of exposed defective sites without redundant post-processing. POM-induced UiO-66 ({P2W18}-0.1@UiO-66) exhibits a classical reo topology for well-defined cluster defects. Moreover, the defective sites and the interaction between POM and skeletal cluster nodes are directly observed by Integrated Differential Phase Contrast in Scanning Transmission Electron Microscopy (iDPC-STEM). Owing to the molecular-level proximity between defective sites and POM in the same nano-reaction space, {P2W18}-0.1@UiO-66 exhibits efficient tandem catalysis in the preparation of γ-valerolactone (γ-GVL) from laevulinic acid (LA) by the combination of Lewis and Brønsted acids with 11 times higher performance than defective UiO-66 formed by conventional coordination modulation strategy. The CCCN strategy is applicable to different POM and has the potential to be extended to other cluster-based MOFs, which will pave a new way for the construction of functional MOFs with multi-centered synergistic catalysis.

14.
Opt Lett ; 49(9): 2237-2240, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38691688

RESUMEN

This Letter reports on investigations of novel, to the best of our knowledge, NiV(Ni93V7)/Ti multilayer mirrors for the operation in the wavelength region of 350-450 eV. Such mirrors are promising optical components for the Z-pinch plasma diagnostic. The NiV/Ti multilayers show superior structural and optical performance compared to conventional Ni/Ti multilayers. Replacing Ni with NiV in multilayers decreases interface widths and enhances the contrast of the refractive index between the absorber and spacer layers. The improvement of interface quality contributes to the enhancement in reflectance. Under the grazing incidence of 13°, a peak reflectivity of 25.1% at 429 eV is achieved for NiV/Ti multilayers, while 17.7% at 427 eV for Ni/Ti.

15.
FASEB J ; 37(2): e22784, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36692416

RESUMEN

Hypoxia-ischemia (HI) is a major cause of brain damage in neonates. Mitochondrial dysfunction acts as a hub for a broad spectrum of signaling events, culminating in cell death triggered by HI. A neuroprotective role of melatonin (MT) has been proposed, and mitophagy regulation seems to be important for cell survival. However, the molecular mechanisms underlying MT-mediated mitophagy during HI treatment are poorly defined. Nucleotide-binding oligomerization domain and leucine-rich repeat-containing protein X1 (NLRX1) has emerged as a critical regulator of mitochondrial dynamics and neuronal death that participates in the pathology of diverse diseases. This study aimed to clarify whether NLRX1 participates in the regulation of mitophagy during MT treatment for hypoxic-ischemic brain damage (HIBD). We demonstrated that MT protected neonates from HIBD through NLRX1-mediated mitophagy in vitro and in vivo. Meanwhile, MT upregulated the expression of NLRX1, Beclin-1, and autophagy-related 7 (ATG7) but decreased the expression of the mammalian target of rapamycin (mTOR) and translocase of the inner membrane of mitochondrion 23 (TIM23). Moreover, the neuroprotective effects of MT were abolished by silencing NLRX1 after oxygen-glucose deprivation (OGD). In addition, the downregulation of mTOR and upregulation of Beclin-1 and ATG7 by MT were inhibited after silencing NLRX1 under OGD. In summary, MT modulates mitophagy induction through NLRX1 and plays a protective role in HIBD, providing insight into potential therapeutic targets for MT to exert neuroprotection.


Asunto(s)
Hipoxia-Isquemia Encefálica , Melatonina , Fármacos Neuroprotectores , Humanos , Recién Nacido , Beclina-1/metabolismo , Encéfalo/metabolismo , Glucosa/farmacología , Hipoxia/tratamiento farmacológico , Hipoxia-Isquemia Encefálica/metabolismo , Leucina/farmacología , Melatonina/farmacología , Proteínas Mitocondriales/genética , Proteínas Mitocondriales/metabolismo , Mitofagia , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Nucleótidos , Oxígeno/farmacología , Serina-Treonina Quinasas TOR/metabolismo
16.
Inorg Chem ; 63(22): 10366-10372, 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38772004

RESUMEN

The accurate manipulation of the species and locations of catalytic centers is crucial for regulating the catalytic activity of catalysts, which is essential for their efficient design and development. Metal-organic frameworks (MOFs) with coordinated metal sites are ideal materials for investigating the origin of catalytic activity. In this study, we present a Ni2-MOF featuring novel Ni-based binuclear nodes with open metal sites (OMSs) and saturated metal sites (SMSs). The nickel was replaced by iron to obtain Ni1Fe1-MOF. In the electrocatalytic oxygen evolution reaction, Ni1Fe1-MOF exhibited an overpotential and Tafel slope of 370 mV@10 mA cm-2 and 87.06 mV dec-1, respectively, which were higher than those of Ni2-MOF (283 mV@10 mA cm-2 and 39.59 mV dec-1, respectively), demonstrating the superior performance of Ni1Fe1-MOF. Furthermore, theoretical calculations revealed that iron as an SMS may effectively regulate the electronic structure of the nickel catalytic center to reduce the free energy barrier ΔG*OH of the rate-determining step.

17.
Environ Sci Technol ; 58(8): 4019-4028, 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38366980

RESUMEN

Humic acid (HA) ubiquitously existing in aquatic environments has been reported to significantly impact permanganate (KMnO4) decontamination processes. However, the underlying mechanism of the KMnO4/HA system remained elusive. In this study, an enhancing effect of HA on the KMnO4 oxidation of diclofenac (DCF) was observed over a wide solution pH range of 5-9. Surprisingly, the mechanism of HA-induced enhancement varied with solution pH. Quenching and chemical probing experiments revealed that manganese intermediates (Mn(III)-HA and MnO2) were responsible for the enhancement under acidic conditions but not under neutral and alkaline conditions. By combining KMnO4 decomposition, galvanic oxidation process experiments, electrochemical tests, and FTIR and XPS analysis, it was interestingly found that HA could effectively mediate the electron transfer from DCF to KMnO4 in neutral and alkaline solutions, which was reported for the first time. The formation of an organic-catalyst complex (i.e., HA-DCF) with lower reduction potential than the parent DCF was proposed to be responsible for the accelerated electron transfer from DCF to KMnO4. This electron transfer likely occurred within the complex molecule formed through the interaction between HA-DCF and KMnO4 (i.e., HA-DCF-KMnO4). These results will help us gain a more comprehensive understanding of the role of HA in the KMnO4 oxidation processes.


Asunto(s)
Óxidos , Contaminantes Químicos del Agua , Óxidos/química , Compuestos de Manganeso/química , Sustancias Húmicas/análisis , Diclofenaco/química , Electrones , Oxidación-Reducción , Contaminantes Químicos del Agua/análisis
18.
Hepatol Res ; 54(2): 142-150, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37706554

RESUMEN

AIM: This study aimed to evaluate the cost-effectiveness of hepatitis E vaccination strategies in chronic hepatitis B (CHB) patients. METHODS: Based on the societal perspective, the cost-effectiveness of three hepatitis E vaccination strategies-vaccination without screening, screening-based vaccination, and no vaccination-among CHB patients was evaluated using a decision tree-Markov model, and incremental cost-effectiveness ratios (ICERs) were calculated. Values for treatment costs and health utilities were estimated from a prior investigation on disease burden, and values for transition probabilities and vaccination-related costs were obtained from previous studies and government agencies. Sensitivity analyses were undertaken for assessing model uncertainties. RESULTS: It was estimated that CHB patients superinfected with hepatitis E virus (HEV) incurred significantly longer disease course, higher economic burden, and more health loss compared to those with HEV infection alone (all p < 0.05). The ICERs of vaccination without screening and screening-based vaccination compared to no vaccination were 41,843.01 yuan/quality-adjusted life year (QALY) and 29,147.32 yuan/QALY, respectively, both lower than China's per-capita gross domestic product (GDP) in 2018. The screening-based vaccination reduced the cost and gained more QALYs than vaccination without screening. One-way sensitivity analyses revealed that vaccine price, vaccine protection rate, and decay rate of vaccine protection had the greatest impact on the cost-effectiveness analysis. Probabilistic sensitivity analyses confirmed the base-case results, and if the willingness-to-pay value reached per-capita GDP, the probability that screening-based vaccination would be cost-effective was approaching 100%. CONCLUSIONS: The disease burden in CHB patients superinfected with HEV is relatively heavy in China, and the screening-based hepatitis E vaccination strategy for CHB patients is the most cost-effective option.

19.
Exp Cell Res ; 431(1): 113738, 2023 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-37572787

RESUMEN

Epithelial-mesenchymal transition (EMT) plays a critical role in hypertension-induced renal fibrosis, a final pathway that leads to end-stage renal failure. C-Atrial natriuretic peptide (ANP)4-23, a specific agonist of natriuretic peptide receptor-C (NPR-C), has been reported to have protective effects against hypertension. However, the role of C-ANP4-23 in hypertension-associated renal fibrosis has not yet been elucidated. In this study, mice were randomly divided into SHAM group, DOCA-salt group and DOCA-salt + C-ANP4-23 group. Renal morphology changes, renal function and fibrosis were detected. Human proximal tubular epithelial cells (HK2) stimulated by aldosterone were used for cell function and mechanism study. The DOCA-salt treated mice exhibited hypertension, kidney fibrosis and renal dysfunction, which were attenuated by C-ANP4-23. Moreover, C-ANP4-23 inhibited DOCA-salt treatment-induced renal EMT as evidenced by decrease of the mesenchymal marker alpha-smooth muscle actin (ACTA2) and vimentin and increase of epithelial cell marker E-cadherin. In HK2 cells, aldosterone induced EMT response, which was also suppressed by C-ANP4-23. The key transcription factors (twist, snail, slug and ZEB1) involved in EMT were increased in the kidney of DOCA-salt-treated mice, which were also suppressed by C-ANP4-23. Mechanistically, C-ANP4-23 inhibited the aldosterone-induced translocation of MR from cytosol to nucleus without change of MR expression. Furthermore, C-ANP4-23 rescued the enhanced expression of NADPH oxidase (NOX) 4 and oxidative stress after aldosterone stimulation. Aldosterone-induced Akt and Erk1/2 activation was also suppressed by C-ANP4-23. Our data suggest that C-ANP4-23 attenuates renal fibrosis, likely through inhibition of MR activation, enhanced oxidative stress and Akt and Erk1/2 signaling pathway.


Asunto(s)
Acetato de Desoxicorticosterona , Hipertensión , Enfermedades Renales , Ratones , Humanos , Animales , Factor Natriurético Atrial/genética , Factor Natriurético Atrial/metabolismo , Receptores del Factor Natriurético Atrial/metabolismo , Aldosterona/efectos adversos , Aldosterona/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Acetato de Desoxicorticosterona/efectos adversos , Hipertensión/inducido químicamente , Hipertensión/metabolismo , Riñón/metabolismo , Enfermedades Renales/inducido químicamente , Enfermedades Renales/prevención & control , Acetatos/efectos adversos , Acetatos/metabolismo , Fibrosis
20.
Environ Res ; 257: 119291, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-38823607

RESUMEN

The presence of butylparaben (BP), a prevalent pharmaceutical and personal care product, in surface waters has raised concerns regarding its impact on aquatic ecosystems. Despite its frequent detection, the toxicity of BP to the cyanobacterium Microcystis aeruginosa remains poorly understood. This study investigates the influence of BP on the growth and physiological responses of M. aeruginosa. Results indicate that low concentrations of BP (below 2.5 mg/L) have negligible effects on M. aeruginosa growth, whereas higher concentrations (5 mg/L and 10 mg/L) lead to significant growth inhibition. This inhibition is attributed to the severe disruption of photosynthesis, evidenced by decreased Fv/Fm values and chlorophyll a content. BP exposure also triggers the production of reactive oxygen species (ROS), resulting in elevated activity of antioxidant enzymes. Excessive ROS generation stimulates the production of microcystin-LR (MC-LR). Furthermore, lipid peroxidation and cell membrane damage indicate that high BP concentrations cause cell membrane rupture, facilitating the release of MC-LR into the environment. Transcriptome analysis reveals that BP disrupts energy metabolic processes, particularly affecting genes associated with photosynthesis, carbon fixation, electron transport, glycolysis, and the tricarboxylic acid cycle. These findings underscore the profound physiological impact of BP on M. aeruginosa and highlight its role in stimulating the production and release of MC-LR, thereby amplifying environmental risks in aquatic systems.


Asunto(s)
Toxinas Marinas , Microcistinas , Microcystis , Parabenos , Fotosíntesis , Microcystis/efectos de los fármacos , Microcystis/crecimiento & desarrollo , Microcystis/metabolismo , Microcistinas/toxicidad , Parabenos/toxicidad , Fotosíntesis/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Contaminantes Químicos del Agua/toxicidad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA