Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 41
Filtrar
Más filtros

Bases de datos
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Mol Cell ; 81(16): 3339-3355.e8, 2021 08 19.
Artículo en Inglés | MEDLINE | ID: mdl-34352206

RESUMEN

Cancer cells selectively promote translation of specific oncogenic transcripts to facilitate cancer survival and progression, but the underlying mechanisms are poorly understood. Here, we find that N7-methylguanosine (m7G) tRNA modification and its methyltransferase complex components, METTL1 and WDR4, are significantly upregulated in intrahepatic cholangiocarcinoma (ICC) and associated with poor prognosis. We further reveal the critical role of METTL1/WDR4 in promoting ICC cell survival and progression using loss- and gain-of-function assays in vitro and in vivo. Mechanistically, m7G tRNA modification selectively regulates the translation of oncogenic transcripts, including cell-cycle and epidermal growth factor receptor (EGFR) pathway genes, in m7G-tRNA-decoded codon-frequency-dependent mechanisms. Moreover, using overexpression and knockout mouse models, we demonstrate the crucial oncogenic function of Mettl1-mediated m7G tRNA modification in promoting ICC tumorigenesis and progression in vivo. Our study uncovers the important physiological function and mechanism of METTL1-mediated m7G tRNA modification in the regulation of oncogenic mRNA translation and cancer progression.


Asunto(s)
Colangiocarcinoma/genética , Proteínas de Unión al GTP/genética , Metiltransferasas/genética , Biosíntesis de Proteínas , Animales , Carcinogénesis/genética , Colangiocarcinoma/patología , Progresión de la Enfermedad , Receptores ErbB/genética , Guanosina/análogos & derivados , Guanosina/genética , Humanos , Ratones , Procesamiento Postranscripcional del ARN/genética , ARN Mensajero/genética , ARN de Transferencia/genética
2.
Hepatology ; 77(4): 1122-1138, 2023 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-35598182

RESUMEN

BACKGROUND AND AIMS: Radiofrequency ablation (RFA) is an important curative therapy in hepatocellular carcinoma (HCC), but recurrence rate remains as high as all the other HCC therapeutic modalities. Methyltransferase 1 (METTL1), an enzyme for m 7 G tRNA modification, was reported to promote HCC development. Here, we assessed the role of METTL1 in shaping the immunosuppressive tumor microenvironment after insufficient RFA (iRFA). APPROACH AND RESULTS: By immunohistochemistry and multiplex immunofluorescence (mIF) staining, we showed that METTL1 expression was enhanced in post-RFA recurrent HCC, accompanied by increased CD11b + CD15 + polymorphonuclear-myeloid-derived suppressor cells (PMN-MDSCs) and decreased CD8 + T cells. Mechanistically, heat-mediated METTL1 upregulation enhanced TGF-ß2 translation to form the immunosuppressive environment by induction of myeloid-derived suppressor cell. Liver-specific overexpression or knockdown of Mettl1 significantly affected the accumulation of PMN-MDSCs and subsequently affected CD8 + T cell infiltration. Complete RFA successfully eliminated the tumor, whereas iRFA-treated mice exhibited enhanced tumor growth and metastasis with increased PMN-MDSC accumulation and decreased CD8 + T cells compared to sham surgery. Interrupting METTL1-TGF-ß2-PMN-MDSC axis by anti-Ly6G antibody, or knockdown of hepatoma-intrinsic Mettl1 or Tgfb2 , or TGF-ß signaling blockade significantly mitigated tumor progression induced by iRFA and restored CD8 + T cell population. CONCLUSIONS: Our study sheds light on the pivotal role of METTL1 in modulating an immunosuppressive microenvironment and demonstrated that interrupting METTL1-TGF-ß2-PMN-MDSC axis could be a therapeutic strategy to restore antitumor immunity and prevent HCC recurrence after RFA treatment, meriting further clinical studies.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Células Supresoras de Origen Mieloide , Ratones , Animales , Carcinoma Hepatocelular/metabolismo , Células Supresoras de Origen Mieloide/metabolismo , Neoplasias Hepáticas/patología , Factor de Crecimiento Transformador beta2/metabolismo , Microambiente Tumoral
3.
Mol Ther ; 31(6): 1596-1614, 2023 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-35965412

RESUMEN

Radiofrequency heat ablation is an ideal radical treatment for hepatocellular carcinoma (HCC). However, insufficient radiofrequency ablation (IRFA) could lead to high recurrence of HCC. N7-methylguanosine (m7G) on tRNAs, an evolutionally conservative modification in mammals and yeast, modulates heat stress responses and tumor progression, while its function in HCC recurrence after IRFA remains unknown. Here, we found that IRFA significantly upregulates the level of m7G tRNA modification and its methyltransferase complex components METTL1/WDR4 in multiple systems including HCC patient-derived xenograft (PDX) mouse, patients' HCC tissues, sublethal-heat-treated models of HCC cell lines, and organoids. Functionally, gain-/loss-of-function assays showed that METTL1-mediated m7G tRNA modification promotes HCC metastasis under sublethal heat exposure both in vitro and in vivo. Mechanistically, we found that METTL1 and m7G tRNA modification enhance the translation of SLUG/SNAIL in a codon frequency-dependent manner under sublethal heat stress. Overexpression of SLUG/SNAIL rescued the malignant potency of METTL1 knockdown HCC cells after sublethal heat exposure. Our study uncovers the key functions of m7G tRNA modification in heat stress responses and HCC recurrence after IRFA, providing molecular basis for targeting METTL1-m7G-SLUG/SNAIL axis to prevent HCC metastasis after radiofrequency heat ablation treatment.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Ablación por Radiofrecuencia , Humanos , Ratones , Animales , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/metabolismo , ARN de Transferencia/genética , Mamíferos , Proteínas de Unión al GTP/metabolismo
4.
Hepatology ; 74(3): 1339-1356, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-33638162

RESUMEN

BACKGROUND AND AIMS: The dynamic N6-methyladenosine (m6 A) mRNA modification is essential for acute stress response and cancer progression. Sublethal heat stress from insufficient radiofrequency ablation (IRFA) has been confirmed to promote HCC progression; however, whether m6 A machinery is involved in IRFA-induced HCC recurrence remains open for study. APPROACH AND RESULTS: Using an IRFA HCC orthotopic mouse model, we detected a higher level of m6 A reader YTH N6-methyladenosine RNA binding protein 1-3 (YTHDF1) in the sublethal-heat-exposed transitional zone close to the ablation center than that in the farther area. In addition, we validated the increased m6 A modification and elevated YTHDF1 protein level in sublethal-heat-treated HCC cell lines, HCC patient-derived xenograft (PDX) mouse model, and patients' HCC tissues. Functionally, gain-of-function/loss-of-function assays showed that YTHDF1 promotes HCC cell viability and metastasis. Knockdown of YTHDF1 drastically restrains the tumor metastasis evoked by sublethal heat treatment in tail vein injection lung metastasis and orthotopic HCC mouse models. Mechanistically, we found that sublethal heat treatment increases epidermal factor growth receptor (EGFR) m6 A modification in the vicinity of the 5' untranslated region and promotes its binding with YTHDF1, which enhances the translation of EGFR mRNA. The sublethal-heat-induced up-regulation of EGFR level was further confirmed in the IRFA HCC PDX mouse model and patients' tissues. Combination of YTHDF1 silencing and EGFR inhibition suppressed the malignancies of HCC cells synergically. CONCLUSIONS: The m6 A-YTHDF1-EGFR axis promotes HCC progression after IRFA, supporting the rationale for targeting m6 A machinery combined with EGFR inhibitors to suppress HCC metastasis after RFA.


Asunto(s)
Carcinoma Hepatocelular/cirugía , Neoplasias Hepáticas/cirugía , Procesamiento Postranscripcional del ARN/efectos de la radiación , ARN Mensajero/metabolismo , Proteínas de Unión al ARN/efectos de la radiación , Ablación por Radiofrecuencia/efectos adversos , Animales , Carcinoma Hepatocelular/genética , Supervivencia Celular/genética , Supervivencia Celular/efectos de la radiación , Receptores ErbB/genética , Receptores ErbB/metabolismo , Receptores ErbB/efectos de la radiación , Regulación Neoplásica de la Expresión Génica , Respuesta al Choque Térmico/efectos de la radiación , Humanos , Neoplasias Hepáticas/genética , Metilación/efectos de la radiación , Ratones , Metástasis de la Neoplasia , Trasplante de Neoplasias , Procesamiento Postranscripcional del ARN/genética , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Insuficiencia del Tratamiento
5.
Physiol Mol Biol Plants ; 28(10): 1875-1887, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36484027

RESUMEN

Liriodendron tulipifera L. is an ornamental tree species with extraordinarily lobed leaves. However, the mechanisms underlying lobed leaf formation in plants remain unclear. The transcription factor, ARABIDOPSIS THALIANA HOMEBOX 6 (HB6), plays a role in regulating leaf margin development. HB6 is involved in cell division and differentiation of developmental organs and negatively regulates abscisic acid (ABA) signal transmission under external abiotic stress; it is unclear whether HB6 performs a pivotal role in leaf morphogenesis in L. tulipifera. In this study, full-length LtuHB6 from L. tulipifera was heterologously expressed in tobacco and Arabidopsis thaliana; its expression pattern was analyzed to determine its potential role in leaf development. In addition, LtuHB6 is localized in the nucleus and cell membrane of tobacco leaves. The expression of LtuHB6 was highest in mature leaves compared to the other stages of leaf development (bud growth, young leaves, and leaf senescence). Transgenic A. thaliana plants overexpressing LtuHB6 exhibited an abnormal phenotype with lobed leaves. Moreover, LtuHB6 overexpression significantly affected the expression of seven genes related to leaf serration in the initial stage of leaf primordia and altered the expression levels of hormonal genes. Our findings indicate that LtuHB6 is an essential regulatory factor in L. tulipifera lobed-leaf formation and is involved in regulating and responding to hormones. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01254-9.

6.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 43(6): 975-979, 2021 Dec 30.
Artículo en Zh | MEDLINE | ID: mdl-34980340

RESUMEN

Tuberculous peritonitis(TBP)is currently one of the common manifestations of extrapulmonary tuberculosis.Due to the atypical clinical features,diverse types of diseases to be distinguished,and limited detection methods,TBP is difficult to be diagnosed and the fatality caused by delayed diagnosis increases significantly.We studied the current research status of TBP and found that T cells spot test,abdominal CT,and laparoscopic biopsy were of high diagnostic value for TBP.However,the application of ascites Xpert-MTB/RIF-ultra assay,ascites ADA,and whole-body positron emission tomography/computed tomography remained to be studied.Serum CA125 helps to judge the efficacy of anti-tuberculosis treatment.


Asunto(s)
Mycobacterium tuberculosis , Peritonitis Tuberculosa , Tuberculosis , Ascitis , Biopsia , Humanos , Peritonitis Tuberculosa/diagnóstico , Sensibilidad y Especificidad , Tuberculosis/diagnóstico
7.
J Gastroenterol Hepatol ; 35(2): 271-277, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31247673

RESUMEN

BACKGROUND AND AIMS: Diagnostic performance of ascitic fluid total protein (AFTP) concentration remained unsettled. Our aim was to determine diagnostic value of AFTP in differential diagnosis of causes of ascites. METHODS: Seven hundred four consecutive patients with new-onset ascites were prospectively enrolled in this study. RESULTS: In the training cohort, diagnostic performance of quantitative AFTP assay was superior to that of Rivalta test in differential diagnosis of ascites. At the predetermined cut-off value of 25 g/L, quantitative AFTP assay was more useful in the differentiation of non-portal hypertensive ascites from portal hypertensive ascites compared with the exudate-transudate classification, area under curve of receiver operating characteristic curve was 0.958. Quantitative AFTP assay was superior to serum-ascites albumin gradient in the detection of non-portal hypertensive ascites, especially malignant ascites and tuberculous peritonitis. In mixed ascites, AFTP was useful in identifying peritoneal lesions. CONCLUSIONS: Ascitic fluid total protein is a useful marker in non-portal hypertensive ascites; thus, it should be determined in diagnostic work-up of the patients with ascites.


Asunto(s)
Ascitis/diagnóstico , Ascitis/etiología , Líquido Ascítico/química , Proteínas/análisis , Biomarcadores/análisis , Diagnóstico Diferencial , Humanos , Hipertensión/complicaciones
8.
Glia ; 64(2): 240-54, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26446044

RESUMEN

Studies have implicated astrocytic dysfunction in Alzheimer's disease (AD). However, the role of astrocytes in the pathophysiology and treatment of the disease is poorly characterized. Here, we identified astrocytes as independent key factors involved in several Alzheimer-like phenotypes in an APP/PS1 mouse model, including amyloid pathology, altered neuronal and synaptic properties, and impaired cognition. In vitro astrocytes from APP/PS1 mice induced synaptotoxicity as well as reduced dendritic complexity and axonal branching of hippocampal neurons. These astrocytes produced high levels of soluble ß-amyloid (Aß) which could be significantly inhibited by fluoxetine (FLX) via activating serotonin 5-HT2 receptors. FLX could also protect hippocampal neurons against astrocyte-induced neuronal damage in vitro. In the same APP/PS1 mice, FLX inhibited activation of astrocytes, lowered Aß products, ameliorated neurotoxicity, and improved behavioral performance. These findings may provide a basis for the clinical application of FLX in patients, and may also lay the groundwork for exploration of other novel astrocyte-based therapies of AD.


Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Astrocitos/efectos de los fármacos , Fluoxetina/farmacología , Fármacos Neuroprotectores/farmacología , Enfermedad de Alzheimer/patología , Enfermedad de Alzheimer/fisiopatología , Péptidos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animales , Astrocitos/patología , Astrocitos/fisiología , Encéfalo/efectos de los fármacos , Encéfalo/patología , Encéfalo/fisiopatología , Células Cultivadas , Modelos Animales de Enfermedad , Humanos , Aprendizaje por Laberinto , Neuronas/efectos de los fármacos , Neuronas/patología , Neuronas/fisiología , Fragmentos de Péptidos/metabolismo , Placa Amiloide/tratamiento farmacológico , Placa Amiloide/patología , Placa Amiloide/fisiopatología , Presenilina-1/genética , Presenilina-1/metabolismo , Receptores de Serotonina 5-HT2/metabolismo
9.
J Neurochem ; 130(6): 780-9, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24862291

RESUMEN

Previous studies have demonstrated that quetiapine (QTP) may have neuroprotective properties; however, the underlying mechanisms have not been fully elucidated. In this study, we identified a novel mechanism by which QTP increased the synthesis of ATP in astrocytes and protected GABAergic neurons from aging-induced death. In 12-month-old mice, QTP significantly improved cell number of GABAegic neurons in the cortex and ameliorated anxiety-like behaviors compared to control group. Complimentary in vitro studies showed that QTP had no direct effect on the survival of aging GABAergic neurons in culture. Astrocyte-conditioned medium (ACM) pretreated with QTP (ACMQTP) for 24 h effectively protected GABAergic neurons against aging-induced spontaneous cell death. It was also found that QTP boosted the synthesis of ATP from cultured astrocytes after 24 h of treatment, which might be responsible for the protective effects on neurons. Consistent with the above findings, a Rhodamine 123 test showed that ACMQTP, not QTP itself, was able to prevent the decrease in mitochondrial membrane potential in the aging neurons. For the first time, our study has provided evidence that astrocytes may be the conduit through which QTP is able to exert its neuroprotective effects on GABAergic neurons. The neuroprotective properties of quetiapine (QTP) have not been fully understood. Here, we identify a novel mechanism by which QTP increases the synthesis of ATP in astrocytes and protects GABAergic neurons from aging-induced death in a primary cell culture model. In 12-month-old mice, QTP significantly improves cell number of GABAegic neurons and ameliorates anxiety-like behaviors. Our study indicates that astrocytes may be the conduit through which QTP exerts its neuroprotective effects on GABAergic neurons.


Asunto(s)
Envejecimiento/psicología , Antipsicóticos/farmacología , Ansiedad/psicología , Astrocitos/fisiología , Conducta Animal/efectos de los fármacos , Dibenzotiazepinas/farmacología , Neuronas/efectos de los fármacos , Sustancias Protectoras , Ácido gamma-Aminobutírico/fisiología , Adenosina Trifosfato/biosíntesis , Adenosina Trifosfato/metabolismo , Animales , Recuento de Células , Supervivencia Celular/efectos de los fármacos , Medios de Cultivo Condicionados , Oscuridad , Conducta Exploratoria/efectos de los fármacos , Femenino , Inmunohistoquímica , Luz , Ratones , Ratones Endogámicos C57BL , Actividad Motora/efectos de los fármacos , Cultivo Primario de Células , Fumarato de Quetiapina , Regulación hacia Arriba/efectos de los fármacos
10.
J Neurochem ; 131(2): 229-38, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24934403

RESUMEN

Serotonin/norepinephrine reuptake inhibitors antidepressants exert their effects by increasing serotonin and norepinephrine in the synaptic cleft. Studies show it takes 2-3 weeks for the mood-enhancing effects, which indicate other mechanisms may underlie their treatment effects. Here, we investigated the role of white matter in treatment and pathogenesis of depression using an unpredictable chronic mild stress (UCMS) mouse model. Desvenlafaxine (DVS) was orally administrated to UCMS mice at the dose of 10 mg/kg/day 1 week before they went through a 7-week stress procedure and lasted for over 8 weeks before the mice were killed. No significant changes were found for protein markers of neurons and astrocytes in UCMS mice. However, myelin and oligodendrocyte-related proteins were significantly reduced in UCMS mice. DVS prevented the stress-induced injury to white matter and the decrease of phosphorylated 5'-AMP-activated protein kinase and 3-hydroxy-3-methyl-glutaryl-CoA reductase protein expression. DVS increased open arm entries in an elevated plus-maze test, sucrose consumption in the sucrose preference test and decreased immobility in tail suspension and forced swimming tests. These findings suggest that stress induces depression-like behaviors and white matter deficits in UCMS mice. DVS may ameliorate the oligodendrocyte dysfunction by affecting cholesterol synthesis, alleviating the depression-like phenotypes in these mice. We examined the possible role of oligodendrocyte and myelin in the pathological changes of depression with an unpredictable chronic mild stress (UCMS) mouse model. Oligodendrocyte-related proteins in the mouse brain were specifically changed during the stress period. The depressive-like behaviors and oligodendrocyte deficits could be prevented by the administration of desvenlafaxine. Oligodendrocyte and myelin may be an essential target of desvenlafaxine for the treatment of depression.


Asunto(s)
Colesterol/biosíntesis , Ciclohexanoles/uso terapéutico , Depresión/tratamiento farmacológico , Depresión/enzimología , Modelos Animales de Enfermedad , Sustancia Blanca/enzimología , Animales , Antidepresivos/farmacología , Antidepresivos/uso terapéutico , Ciclohexanoles/farmacología , Depresión/patología , Succinato de Desvenlafaxina , Femenino , Ratones , Ratones Endogámicos C57BL , Fosforilación/efectos de los fármacos , Fosforilación/fisiología , Distribución Aleatoria , Sustancia Blanca/efectos de los fármacos , Sustancia Blanca/patología
11.
Int J Neuropsychopharmacol ; 18(3)2014 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-25618401

RESUMEN

BACKGROUND: In Alzheimer's disease, growing evidence has shown that uncontrolled glial activation and neuroinflammation may contribute independently to neurodegeneration. Antiinflammatory strategies might provide benefits for this devastating disease. The aims of the present study are to address the issue of whether glial activation and proinflammatory cytokine increases could be modulated by quetiapine in vivo and in vitro and to explore the underlying mechanism. METHODS: Four-month-old amyloid precursor protein (APP) and presenilin 1 (PS1) transgenic and nontransgenic mice were treated with quetiapine (5mg/kg/d) in drinking water for 8 months. Animal behaviors, total Aß levels, and glial activation were evaluated by behavioral tests, enzyme-linked immunosorbent assay, immunohistochemistry, and Western blot accordingly. Inflammatory cytokines and the nuclear factor kappa B pathway were analyzed in vivo and in vitro. RESULTS: Quetiapine improves behavioral performance, marginally affects total Aß40 and Aß42 levels, attenuates glial activation, and reduces proinflammatory cytokines in APP/PS1 mice. Quetiapine suppresses Aß1-42-induced activation of primary microglia by decresing proinflammatory cytokines. Quetiapine inhibits the activation of nuclear factor kappa B p65 pathway in both transgenic mice and primary microglia stimulated by Aß1-42. CONCLUSIONS: The antiinflammatory effects of quetiapine in Alzheimer's disease may be involved in the nuclear factor kappa B pathway. Quetiapine may be an efficacious and promising treatment for Alzheimer's disease targeting on neuroinflammation.


Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Citocinas/metabolismo , Dibenzotiazepinas , Microglía/efectos de los fármacos , FN-kappa B/metabolismo , Transducción de Señal/efectos de los fármacos , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/metabolismo , Péptidos beta-Amiloides/farmacología , Precursor de Proteína beta-Amiloide/genética , Animales , Antipsicóticos/farmacología , Antipsicóticos/uso terapéutico , Células Cultivadas , Corteza Cerebral/citología , Dibenzotiazepinas/farmacología , Dibenzotiazepinas/uso terapéutico , Modelos Animales de Enfermedad , Conducta Exploratoria/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica/genética , Humanos , Ratones , Ratones Transgénicos , Mutación/genética , Presenilina-1/genética , Fumarato de Quetiapina , Reconocimiento en Psicología/efectos de los fármacos
12.
Neurochem Res ; 39(12): 2385-93, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25270429

RESUMEN

Use of phencyclidine (PCP) in rodents can mimic some aspects of schizophrenia. However, the underlying mechanism is still unclear. Growing evidence indicates that neuroinflammation plays a significant role in the pathophysiology of schizophrenia. In this study, we focused on inflammatory responses as target of PCP for inducing schizophrenia-like symptoms. 3-month-old C57BL/6J mice received daily injections of PCP (20 mg/kg, i.p.) or saline for one week. PCP-injected mice produced schizophrenia-like behaviours including impaired spatial short-term memory assessed by the Y-maze task and sensorimotor gating deficits in a prepulse inhibition task. Simultaneously, chronic PCP administration induced astrocyte and microglial activation in both the cortex and hippocampus. Additionally, the proinflammatory cytokine interleukin-1ß was significantly up-regulated in PCP administrated mice. Furthermore, PCP treatment decreased ratio of the phospho-Ser9 epitope of glycogen synthase kinase-3ß (GSK3ß) over total GSK3ß, which is indicative of increased GSK3ß activity. These data demonstrate that chronic PCP in mouse produces inflammatory responses and GSK3ß activation.


Asunto(s)
Glucógeno Sintasa Quinasa 3/metabolismo , Inflamación/inducido químicamente , Fenciclidina/toxicidad , Animales , Activación Enzimática , Glucógeno Sintasa Quinasa 3 beta , Ratones
13.
Dalton Trans ; 52(31): 10885-10894, 2023 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-37486320

RESUMEN

The development of productive and sustainable bifunctional electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) plays an important role in the commercial evolution of metal-air batteries. In this paper, a low-temperature molten salt template method was adopted to synthesize the composite of CoS2 and nitrogen-doped carbon (CoS2/NC) without the protection of inert gas. The structural characterization studies show that the specific surface area (SSA) and crystal growth kinetics are increased and effectively improved, respectively, by the composite of CoS2 and NC. The as-synthesized CoS2/NC composite demonstrates outstanding bifunctional catalytic activity in alkaline electrolytes and exhibits a half-wave potential (E1/2) of 0.854 V (vs. RHE) and an overpotential of only 220 mV for the OER at a current density of 10 mA cm-2 (η10). Simultaneously, CoS2/NC also exhibits excellent electrochemical stability. Additionally, density functional theory (DFT) calculations have manifested that the synergistic effect of CoS2 and NC results in a remarkable enhancement in the bifunctional catalytic performance of the composite materials. This study offers a new pathway and theoretical guidance for the fabrication of efficient bifunctional electrocatalysts.

14.
Cell Death Discov ; 9(1): 25, 2023 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-36690649

RESUMEN

Type 1 T helper (Th1) cells generate an efficient antitumor immune response in multiple malignancies. The functions of Th1 cells in malignant ascites (MA) have not been elucidated. The distribution of helper T cells in peritoneal fluid and peripheral blood was determined in patients and animal models with malignant ascites. The effects of Th1-derived interferon-γ (IFN-γ) on the formation of malignant ascites were investigated. The mechanism underlying the recruitment of Th1 cells into peritoneal cavity was explored. In patients with malignant ascites and animal models of malignant ascites, the percentage of Th1 cells increased in peritoneal fluid compared with peripheral blood. Next, our experiment demonstrated that Th1 cells inhibited the growth of tumor cells by secreting IFN-γ in vitro. In murine models of malignant ascites, increased peritoneal fluid and shorter survival time were observed in IFN-γ-/- mice compared with wild-type (WT) mice. Then, the levels of C-X-C motif chemokine ligand (CXCL) 9/10 and the ratio of CXCR3+ Th1 cells indicated the involvement of CXCL9, 10/CXCR3 axis in the recruitment of Th1 cells into peritoneal cavity. As expected, in murine models of malignant ascites, the gradient between ascitic Th1 ratio and blood Th1 ratio decreased in CXCR3-/- mice compared with WT mice. IFN-γ secreted by recruited Th1 cells in peritoneal cavity inhibits the formation of malignant ascites. Hence, manipulation of Th1 cells or IFN-γ will provide a therapeutic candidate against malignant ascites.

15.
Cell Rep Med ; 4(11): 101277, 2023 11 21.
Artículo en Inglés | MEDLINE | ID: mdl-37944531

RESUMEN

Patients with biliary tract cancer (BTC) show different responses to chemotherapy, and there is no effective way to predict chemotherapeutic response. We have generated 61 BTC patient-derived organoids (PDOs) from 82 tumors (74.4%) that show similar histological and genetic characteristics to the corresponding primary BTC tissues. BTC tumor tissues with enhanced stemness- and proliferation-related gene expression by RNA sequencing can more easily form organoids. As expected, BTC PDOs show different responses to the chemotherapies of gemcitabine, cisplatin, 5-fluoruracil, oxaliplatin, etc. The drug screening results in PDOs are further validated in PDO-based xenografts and confirmed in 92.3% (12/13) of BTC patients with actual clinical response. Moreover, we have identified gene expression signatures of BTC PDOs with different drug responses and established gene expression panels to predict chemotherapy response in BTC patients. In conclusion, BTC PDO is a promising precision medicine tool for anti-cancer therapy in BTC patients.


Asunto(s)
Neoplasias del Sistema Biliar , Detección Precoz del Cáncer , Humanos , Evaluación Preclínica de Medicamentos , Gemcitabina , Neoplasias del Sistema Biliar/tratamiento farmacológico , Neoplasias del Sistema Biliar/genética , Neoplasias del Sistema Biliar/patología , Organoides/patología
16.
Phytother Res ; 26(10): 1528-33, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22322985

RESUMEN

Excessive activation of microglial cells has been implicated in various types of neuroinflammation. Suppression of microglial activation would have therapeutic benefits, leading to the alleviation of the progression of neurodegeneration. In this study, the inhibitory effects of rhynchophylline (RIN), a tetracyclic oxindole alkaloid component isolated from Uncaria rhynchophylla (Miq.) Jacks., on the production of pro-inflammatory mediators were investigated in lipopolysaccharide (LPS)-stimulated microglia. The results showed that RIN markedly reduced the production of nitric oxide (NO), prostaglandins E(2) (PGE(2) ), monocyte chemoattractant protein (MCP-1), tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) in LPS-activated microglia. The mRNA expression levels of iNOS and COX-2 were also depressed by RIN in a concentration-dependent manner. Further studies revealed that RIN blocked IκBα phosphorylation and degradation, inhibited the phosphorylation of mitogen-activated protein kinases (MAPKs). In summary, these data suggest that RIN suppresses inflammatory responses of microglia and may act as a potential therapeutic agent for various neurodegenerative diseases involving neuroinflammation.


Asunto(s)
Alcaloides Indólicos/farmacología , Mediadores de Inflamación/metabolismo , Inflamación/metabolismo , Microglía/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Animales , Supervivencia Celular , Células Cultivadas , Quimiocina CCL2/metabolismo , Ciclooxigenasa 2/metabolismo , Dinoprostona/biosíntesis , Regulación hacia Abajo , Proteínas I-kappa B , Interleucina-1beta/biosíntesis , Lipopolisacáridos , Sistema de Señalización de MAP Quinasas , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , Inhibidor NF-kappaB alfa , FN-kappa B/antagonistas & inhibidores , Óxido Nítrico/biosíntesis , Óxido Nítrico Sintasa de Tipo II/metabolismo , Oxindoles , Fosforilación , Ratas , Factor de Necrosis Tumoral alfa/biosíntesis
17.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 3): o661, 2011 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-21522412

RESUMEN

The title compound pteleifolosin C, C(21)H(20)O(7), was isolated from the petroleum ether-soluble fraction of an indigenous Chinese tree Melicope pteleifolia (Rutaceae). The dihedral angle between the benzene rings is 2.7 (2)°. Intra-molecular O-H⋯O hydrogen bonds occur. In the crystal, mol-ecules are linked by inter-molecular O-H-O hydrogen bonds.

18.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 4337-4340, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34892181

RESUMEN

Transcranial direct current stimulation (tDCS) delivers weak current into the brain to modulate neural activities. Many methods have been proposed to determine electrode positions and stimulation intensities. Due to the trade-off between intensity and focality, it is actually a multi-objective optimization problem that has a set of optimal solutions. However, traditional methods can produce only one solution at each time, and many parameters need to be determined by experience. In this study, we proposed the nondominated sorting genetic algorithm II (NSGA-II) to solve the current optimization problem of multi-electrode tDCS. We also compared the representative solutions with LCMV solutions. The result shows that a group of solutions close to the optimal front can be obtained just in only one run without any prior knowledge.


Asunto(s)
Estimulación Transcraneal de Corriente Directa , Algoritmos , Encéfalo , Electrodos , Cabeza
19.
Clin Neurophysiol Pract ; 6: 275-280, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34825115

RESUMEN

OBJECTIVES: In refractory status epilepticus (RSE), the optimal degree of suppression (EEG burst suppression or merely suppressing seizures) remains unknown. Many centers lacking continuous EEG must default to serial intermittent recordings where uncertainty from lack of data may prompt more aggressive suppression. In this study, we sought to determine whether the quantitative burst suppression ratio (QBSR) from serial intermittent EEG recording is associated with RSE patient outcome. METHODS: We screened the EEG database to identify non-anoxic adult RSE patients for EEG and chart review. QBSR was calculated per 10-second EEG epoch as the percentage of time during which EEG amplitude was <3 µV. Patients who survived 1-3 months after discharge from ICU and hospital comprised the favorable group. Further to initial unadjusted univariate analysis of all pooled QBSR, we conducted multivariate analyses to account for individual patient confounders ("per-capita analysis"), uneven number of EEG recordings ("per-session analysis"), and uneven number of epochs ("per-epoch analysis"). We analyzed gender, anesthetic number, and adjusted status epilepticus severity score (aSTESS) as confounders. RESULTS: In 135,765 QBSR values over 160 EEG recordings (median 2.17 h every ≥24 h) from 17 patients on Propofol, Midazolam, and/or Ketamine, QBSR was deeper in the favorable group (p < 0.001) on initial unadjusted analysis. However, on adjusted multivariate analysis, there was consistently no association between QBSR and outcome. Higher aSTESS consistently associated with unfavorable outcome on per-capita (p = 0.033), per-session (p = 0.048) and per-epoch (p < 0.001) analyses. Greater maximal number of non-barbiturate anesthetic associated with favorable outcome on per-epoch analysis (p < 0.001). CONCLUSIONS: There was no association between depth of EEG suppression using non-barbiturate anesthetic and RSE patient outcome based on QBSR from serial intermittent EEG. A per-epoch association between non-barbiturate anesthetic and favorable outcome suggests an effect from non-suppressive time-varying EEG content. SIGNIFICANCE: Targeting and following deeper burst suppression through non-barbiturate anesthetics on serial intermittent EEG monitoring of RSE is of limited utility.

20.
Sci Rep ; 11(1): 6585, 2021 03 22.
Artículo en Inglés | MEDLINE | ID: mdl-33753780

RESUMEN

The organogenesis and development of reproductive organs, i.e., stamen and gynoecium, are important floral characteristics that are closely related to pollinators and reproductive fitness. As a genus from Magnoliaceae, Liriodendron has only two relict species: L. chinense and L. tulipifera. Despite the similar flower shapes of these species, their natural seed-setting rates differ significantly, implying interspecies difference in floral organogenesis and development. MADS-box genes, which participate in floral organogenesis and development, remain unexplored in Liriodendron. Here, to explore the interspecies difference in floral organogenesis and development and identify MADS-box genes in Liriodendron, we examined the stamen and gynoecium primordia of the two Liriodendron species by scanning electron microscopy combined with paraffin sectioning, and then collected two types of primordia for RNA-seq. A total of 12 libraries were constructed and 42,268 genes were identified, including 35,269 reference genes and 6,999 new genes. Monoterpenoid biosynthesis was enriched in L. tulipifera. Genome-wide analysis of 32 MADS-box genes was conducted, including phylogenetic trees, exon/intron structures, and conserved motif distributions. Twenty-six genes were anchored on 17 scaffolds, and six new genes had no location information. The expression profiles of MIKC-type genes via RT-qPCR acrossing six stamen and gynoecium developmental stages indicates that the PI-like, AG/STK-like, SEP-like, and SVP-like genes may contribute to the species-specific differentiation of the organogenesis and development of reproductive organs in Liriodendron. Our findings laid the groundwork for the future exploration of the mechanism underlying on the interspecific differences in reproductive organ development and fitness in Liriodendron.


Asunto(s)
Flores/genética , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Liriodendron/genética , Proteínas de Dominio MADS/genética , Desarrollo de la Planta/genética , Biología Computacional/métodos , Flores/citología , Flores/ultraestructura , Ontología de Genes , Genoma de Planta , Estudio de Asociación del Genoma Completo , Genómica/métodos , Anotación de Secuencia Molecular , Fenotipo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA