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1.
Immunity ; 54(6): 1168-1185.e8, 2021 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-34038747

RESUMEN

Chronic inflammation plays a central role in hepatocellular carcinoma (HCC), but the contribution of hepatocytes to tumor-associated inflammation is not clear. Here, we report that the zinc finger transcription factor Miz1 restricted hepatocyte-driven inflammation to suppress HCC, independently of its transcriptional activity. Miz1 was downregulated in HCC mouse models and a substantial fraction of HCC patients. Hepatocyte-specific Miz1 deletion in mice generated a distinct sub-group of hepatocytes that produced pro-inflammatory cytokines and chemokines, which skewed the polarization of the tumor-infiltrating macrophages toward pro-inflammatory phenotypes to promote HCC. Mechanistically, Miz1 sequestrated the oncoprotein metadherin (MTDH), preventing MTDH from promoting transcription factor nuclear factor κB (NF-κB) activation. A distinct sub-group of pro-inflammatory cytokine-producing hepatocytes was also seen in a subset of HCC patients. In addition, Miz1 expression inversely correated with disease recurrence and poor prognosis in HCC patients. Our findings identify Miz1 as a tumor suppressor that prevents hepatocytes from driving inflammation in HCC.


Asunto(s)
Carcinogénesis/metabolismo , Carcinoma Hepatocelular/metabolismo , Hepatocitos/metabolismo , Inflamación/metabolismo , Neoplasias Hepáticas/metabolismo , Activación de Macrófagos/fisiología , Proteínas Inhibidoras de STAT Activados/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Animales , Carcinogénesis/patología , Carcinoma Hepatocelular/patología , Línea Celular , Línea Celular Tumoral , Quimiocinas/metabolismo , Regulación hacia Abajo/fisiología , Femenino , Células HEK293 , Hepatocitos/patología , Humanos , Inflamación/patología , Hígado/metabolismo , Hígado/patología , Neoplasias Hepáticas/patología , Masculino , Ratones , Ratones Endogámicos C57BL , FN-kappa B/metabolismo , Transducción de Señal/fisiología , Factores de Transcripción/metabolismo , Dedos de Zinc/fisiología
2.
Nano Lett ; 24(17): 5317-5323, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38635037

RESUMEN

Exploring high-efficiency photocatalysts for selective CO2 reduction is still challenging because of the limited charge separation and surface reactions. In this study, a noble-metal-free metallic VSe2 nanosheet was incorporated on g-C3N4 to serve as an electron capture and transfer center, activating surface active sites for highly efficient and selective CO2 photoreduction. Quasi in situ X-ray photoelectron spectroscopy (XPS), soft X-ray absorption spectroscopy (sXAS), and femtosecond transient absorption spectroscopy (fs-TAS) unveiled that VSe2 could capture electrons, which are further transferred to the surface for activating active sites. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and density functional theory (DFT) calculations revealed a kinetically feasible process for the formation of a key intermediate and confirmed the favorable production of CO on the VSe2/PCN (protonated C3N4) photocatalyst. As an outcome, the optimized VSe2/PCN composite achieved 97% selectivity for solar-light-driven CO2 conversion to CO with a high rate of 16.3 µmol·g-1·h-1, without any sacrificial reagent or photosensitizer. This work offers new insights into the photocatalyst design toward highly efficient and selective CO2 conversion.

3.
Cell ; 137(6): 1018-31, 2009 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-19524506

RESUMEN

Retinoblastomas result from the inactivation of the RB1 gene and the loss of Rb protein, yet the cell type in which Rb suppresses retinoblastoma and the circuitry that underlies the need for Rb are undefined. Here, we show that retinoblastoma cells express markers of postmitotic cone precursors but not markers of other retinal cell types. We also demonstrate that human cone precursors prominently express MDM2 and N-Myc, that retinoblastoma cells require both of these proteins for proliferation and survival, and that MDM2 is needed to suppress ARF-induced apoptosis in cultured retinoblastoma cells. Interestingly, retinoblastoma cell MDM2 expression was regulated by the cone-specific RXRgamma transcription factor and a human-specific RXRgamma consensus binding site, and proliferation required RXRgamma, as well as the cone-specific thyroid hormone receptor-beta2. These findings provide support for a cone precursor origin of retinoblastoma and suggest that human cone-specific signaling circuitry sensitizes to the oncogenic effects of RB1 mutations.


Asunto(s)
Proliferación Celular , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Retinoblastoma/metabolismo , Transducción de Señal , Animales , Supervivencia Celular , Humanos , Ratones , Trasplante de Neoplasias , Proteínas Proto-Oncogénicas c-myc/metabolismo , Células Fotorreceptoras Retinianas Conos/metabolismo , Receptor gamma X Retinoide/metabolismo , Receptores beta de Hormona Tiroidea/metabolismo , Trasplante Heterólogo
4.
Int J Biometeorol ; 68(6): 1073-1079, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38438698

RESUMEN

As a significant sector within the tourism industry, desert tourism has developed rapidly in recent years, contributing significantly to local economic development. On the other hand, desert tourism is constantly influenced by the desert climate, characterized by high temperatures, aridity, and dust events. This study examines and analyzes the impact of dust events on the Holiday Climate Index (HCI) using an improved methodology. It incorporates comprehensive meteorological data including temperature, relative humidity, cloud cover, precipitation, wind speed and dust events of Tazhong, located in the heart of the Taklimakan Desert. The results indicate that the maximum mean monthly HCI dips from an ideal level (91) to a very good level (73), the minimum dips from good level (66) to a marginal level (47), and the annual comfortable days (HCI ≥ 80) decrease from 180.5 to 95.3 after considering the impacts of dust events. The corrective HCI indicates that autumn, especially October, offers relatively comfortable climatic conditions for tourism, with the mean monthly comfortable days reach 20.1. These findings can better guide desert tourism activities and also demonstrate that the impact of dust weather on tourism activities cannot be ignored.


Asunto(s)
Clima Desértico , Polvo , Vacaciones y Feriados , Polvo/análisis , China , Turismo
5.
J Hepatol ; 79(5): 1172-1184, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37473847

RESUMEN

BACKGROUND & AIMS: Tumor-associated macrophages (TAMs) are indispensable in the hepatocellular carcinoma (HCC) tumor microenvironment. Xanthine oxidoreductase (XOR), also known as xanthine dehydrogenase (XDH), participates in purine metabolism, uric acid production, and macrophage polarization to a pro-inflammatory phenotype. However, the role of XOR in HCC-associated TAMs is unclear. METHODS: We evaluated the XOR level in macrophages isolated from HCC tissues and paired adjacent tissues. We established diethylnitrosamine/carbon tetrachloride (CCl4)-induced and orthotopically implanted HCC mouse models using mice with Xdh-specific depletion in the myeloid cell lineage (Xdhf/fLyz2cre) or Kupffer cells (Xdhf/fClec4fcre). We determined metabolic differences using specific methodologies, including metabolomics and metabolic flux. RESULTS: We found that XOR expression was downregulated in HCC TAMs and positively correlated with patient survival, which was strongly related to the characteristics of the tumor microenvironment, especially hypoxia. Using HCC-inflicted mice (Xdhf/fLyz2cre and Xdhf/fClec4fcre), we revealed that XOR loss in monocyte-derived TAMs rather than Kupffer cells promoted their M2 polarization and CD8+ T-cell exhaustion, which exacerbated HCC progression. In addition, the tricarboxylic acid cycle was disturbed, and the generation of α-ketoglutarate was enhanced within XOR-depleted macrophages. XOR inhibited α-ketoglutarate production by interacting with IDH3α catalytic sites (K142 and Q139). The increased IDH3α activity caused increased adenosine and kynurenic acid production in TAMs, which enhanced the immunosuppressive effects of TAMs and CD8+ T cells. CONCLUSIONS: The XOR-IDH3α axis mediates TAM polarization and HCC progression and may be a small-molecule therapeutic or immunotherapeutic target against suppressive HCC TAMs. IMPACT AND IMPLICATIONS: Immunotherapies have been widely applied to the treatment of hepatocellular carcinoma (HCC), but to date they have been associated with unsatisfactory efficacy. The tumor microenvironment of HCC is full of different infiltrating immune cells. Tumor-associated macrophages (TAMs) are vital components in the tumor microenvironment and are involved in HCC progression. Herein, we confirm the downregulation of XOR expression in TAMs isolated from human HCC. The loss of XOR in monocyte-derived macrophages increases IDH3 activity and results in an increase in α-ketoglutarate production, which can promote M2-like polarization. Additionally, XOR-null TAMs derived from monocytes promote CD8+ T-cell exhaustion via the upregulation of immunosuppressive metabolites, including adenosine and kynurenic acid. Given the prevalence and high rate of incidence of HCC and the need for improved therapeutic options for patients, our findings identify potential therapeutic targets that may be further studied to develop improved therapies.

6.
Pak J Pharm Sci ; 36(2(Special)): 631-638, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37548201

RESUMEN

This study is to evaluate the effect of receptor for activated c kinase 1 (RACK1) and peripheral blood M2/M1 monocytes ratio on the prognosis of patients with oral squamous cell carcinoma (OSCC). A total of 115 OSCC patients who underwent radical surgery in North China University of Science and Technology Affiliated Hospital from January 2015 to December 2015 were included in the experimental group and 34 healthy individuals after a physical examination during the same period were included in the control group. Cancer and para-cancerous tissues were collected and the relationship between RACK1 and M2/M1 ratio and the prognosis of OSCC patients and its predictive value were analyzed. RACK1, M2/M1 ratio, clinical stages, lymphatic metastasis, recurrence and metastasis were considered independent factors for the prognosis of OSCC patients (p<0.05); In addition, RACK1 and the M2/M1 ratio were proven to be of significant predictive values for the prognosis of OSCC patients (p<0.05). RACK1 and peripheral blood M2/M1 monocytes ratio demonstrate great potential as prognostic predictors of OSCC patients.


Asunto(s)
Monocitos , Neoplasias de la Boca , Receptores de Cinasa C Activada , Carcinoma de Células Escamosas de Cabeza y Cuello , Humanos , Biomarcadores de Tumor , Monocitos/patología , Neoplasias de la Boca/cirugía , Neoplasias de la Boca/patología , Proteínas de Neoplasias , Pronóstico , Carcinoma de Células Escamosas de Cabeza y Cuello/patología , Carcinoma de Células Escamosas de Cabeza y Cuello/cirugía
7.
BMC Cancer ; 22(1): 1027, 2022 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-36175877

RESUMEN

The protein Talin1 encoded by the TLN1 gene is a focal adhesion-related protein that binds to various cytoskeletal proteins and plays an important role in cell adhesion and movement. Recent studies have shown that it is overexpressed in prostate cancer, liver cancer, and oral squamous cell carcinoma, and is closely related to tumor progression and metastasis. This study integrated bioinformatics and functional analysis to reveal the prognosis and potential functions of TLN1 in AML. The results showed that the expression level of TLN1 was abnormally increased in AML and localized in the cell membrane and cytoplasm, and TLN1 is a significant prognostic indicator of overall survival (OS). Enrichment analysis of related genes showed that TLN1 is related to neutrophil mediated immunity, neutrophil activation and may regulate important signal pathways in hematological tumors including tyrosine kinase receptor, FLT3 and PIK3/AKT. The PPI network shows that TLN1 and MYH9 may be involved in the process of AML tumors together with PIP5K1C, ROCK1, S100A4, MY01A and WAC. Immune infiltration analysis explains that TLN1 is associated with multiple immune cells and may be an important immune marker in AML. Furthermore, molecular biology experiments confirmed that TLN1 is related to the proliferation, differentiation and cycle of AML cells. Silencing TLN1 can inhibit the proliferation of AML cells and promote differentiation through the Talin1/P-AKT/CREB signaling pathway.


Asunto(s)
Carcinoma de Células Escamosas , Leucemia Mieloide Aguda , Neoplasias de la Boca , Proliferación Celular/genética , Proteínas del Citoesqueleto , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Masculino , Pronóstico , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas Tirosina Quinasas Receptoras , Talina/genética , Talina/metabolismo , Quinasas Asociadas a rho
8.
BMC Gastroenterol ; 22(1): 544, 2022 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-36577952

RESUMEN

BACKGROUND: Microvascular invasion (MVI) is important in early recurrence and leads to poor overall survival (OS) in hepatocellular carcinoma (HCC). A number of studies have reported independent risk factors for MVI. In this retrospective study, we designed to develop a preoperative model for predicting the presence of MVI in HCC patients to help surgeons in their surgical decision-making and improve patient management. PATIENTS AND METHODS: We developed a predictive model based on a nomogram in a training cohort of 225 HCC patients. We analyzed patients' clinical information, laboratory examinations, and imaging features from contrast-enhanced CT. Mann-Whitney U test and multiple logistic regression analysis were used to confirm independent risk factors and develop the predictive model. Internal and external validation was performed on 75 and 77 HCC patients, respectively. Moreover, the diagnostic performance of our model was evaluated using receiver operating characteristic (ROC) curves. RESULTS: In the training cohort, maximum tumor diameter (> 50 mm), tumor margin, direct bilirubin (> 2.7 µmol/L), and AFP (> 360.7 ng/mL) were confirmed as independent risk factors for MVI. In the internal and external validation cohort, the developed nomogram model demonstrated good diagnostic ability for MVI with an area under the curve (AUC) of 0.723 and 0.829, respectively. CONCLUSION: Based on routine clinical examinations, which may be helpful for clinical decision-making, we have developed a nomogram model that can successfully assess the risk of MVI in HCC patients preoperatively. When predicting HCC patients with a high risk of MVI, the surgeons may perform an anatomical or wide-margin hepatectomy on the patient.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagen , Carcinoma Hepatocelular/cirugía , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/cirugía , Estudios Retrospectivos , Invasividad Neoplásica , Tomografía Computarizada por Rayos X/métodos
9.
J Chem Phys ; 156(15): 154116, 2022 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-35459287

RESUMEN

We report a surface hopping approach in which the implemented linear vibronic coupling Hamiltonian is constructed and the electronic wavefunction is propagated in the reciprocal space. The parameters of the linear vibronic coupling model, including onsite energies, phonon frequencies, and electron-phonon couplings, are calculated with density-functional theory and density-functional perturbation theory and interpolated in fine sampling points of the Brillouin zone with maximally localized Wannier functions. Using this approach, we studied the relaxation dynamics of the photo-excited hot carrier in a one-dimensional periodic carbon chain. The results show that the completeness of the number of Hilbert space k points and the number of phonon q points plays an important role in the hot carrier relaxation processes. By calculating the relaxation times of hot carriers under different reciprocal space sampling and extrapolating with the stretched-compressed exponential function, the relaxation times of hot electrons and holes in the quasi-continuous energy band are obtained. By considering the feedback effect in the hopping processes and analyzing the time-dependent phonon energy in different normal modes, we found that the long-wave longitudinal optical phonons play a major role in the relaxation dynamics of hot electrons and holes. We, therefore, provided herein an efficient and accurate approach for modeling the photophysical processes in periodic solid-state material systems.

10.
Hepatology ; 71(6): 2033-2049, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-31578733

RESUMEN

BACKGROUND AND AIMS: Liver cancer stem cells (CSCs) exist in the tumor environment and are critically involved in the initiation and progression of hepatocellular carcinoma (HCC). However, the underlying molecular mechanisms of self-renewal and maintenance of liver CSCs remain poorly understood. APPROACH AND RESULTS: We identified that xanthine oxidoreductase (XOR), which was expressed at low levels in human HCC samples and liver CSCs, restrained HCC formation and chemoresistance by attenuating liver CSC propagation. Mechanistically, XOR physically interacts with ubiquitin-specific peptidase 15 (USP15), thereby promoting deubiquitination of Kelch-like ECH associated protein 1 (KEAP1) to stabilize its expression, which leads to degradation of Nrf2 (nuclear factor erythroid 2-related factor 2) through ubiquitination and subsequently reactive oxygen species accumulation in liver CSCs. Finally, our data reveal that XOR promotes USP15-mediated Nrf2-KEAP1 signaling to block liver CSCs and tumor propagation. CONCLUSION: We identified that XOR may represent a potential therapeutic target for clinical intervention in HCC driven by liver CSCs.


Asunto(s)
Carcinoma Hepatocelular , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Neoplasias Hepáticas , Factor 2 Relacionado con NF-E2/metabolismo , Células Madre Neoplásicas/metabolismo , Proteasas Ubiquitina-Específicas/metabolismo , Xantina Deshidrogenasa/metabolismo , Animales , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/terapia , Autorrenovación de las Células , Descubrimiento de Drogas , Resistencia a Antineoplásicos , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/terapia , Ratones , Transducción de Señal , Células Tumorales Cultivadas , Ubiquitinación
11.
J Org Chem ; 2021 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-34133155

RESUMEN

Mediated by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), a novel oxidative coupling of hydrazones and 1,3-diarylpropenes has been disclosed to generate appealing ß,γ-unsaturated hydrazones, which further undergo 5-exo-trig or 6-endo-trig cascade cyclization to give the respective 1,2-dihydropyridazines or pyrazoles selectively under metal-free conditions. The mechanisms of the coupling and subsequent cyclization are proposed.

12.
BMC Infect Dis ; 21(1): 801, 2021 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-34380453

RESUMEN

BACKGROUND: The management strategy of Bacille Calmette-Guérin (BCG) vaccine-induced regional suppurative lymphadenitis in children is still controversial and more clinical studies are needed. We therefore present a surgical case series to explore the role of surgical management for this dilemma. METHODS: From January 2013 to June 2020, data from 65 patients diagnosed with BCG vaccine-induced regional suppurative lymphadenitis were retrospectively reviewed. Clinical characteristics, ultrasonographic findings, surgical procedures, perioperative management, and outcome were analyzed. The association between postoperative seroma and symptom duration, skin involvement, and postoperative hospital stay were compared using Yates's corrected Chi-square test and Student's t-test for statistical analysis. The follow-up period ranged from three to six months. RESULTS: Of the 65 cases, the median age at presentation was 3.4 months. All patients were full-term with normal range of birth weight and received a BCG vaccination in the first 24 h of life. All patients underwent surgical excision of the abscess with the involved lymph node(s). Postoperative seroma formation was found in 20 patients and fine needle aspiration was needed. There was no significant association between postoperative seroma formation with symptom duration, skin involvement, and postoperative hospital stay. No oral anti-tubercular agents were given postoperatively. The mean length of postoperative hospital stay was 6.02 ± 1.62 days. Sixty-four cases (98.46%) received only one procedure and recovered. One patient required a second procedure due to postoperative sinus. CONCLUSIONS: The present study showed that surgical excision of the abscess with involved lymph node(s) is one of the choices for BCG vaccine-induced suppurative lymphadenitis, but special attention should be paid to controlling the surgical indications. Intraoperative meticulous manipulation and postoperative care are crucial to achieve a good outcome.


Asunto(s)
Vacuna BCG , Linfadenitis , Vacuna BCG/efectos adversos , Niño , Humanos , Lactante , Ganglios Linfáticos , Linfadenitis/inducido químicamente , Estudios Retrospectivos , Vacunación/efectos adversos
13.
Angew Chem Int Ed Engl ; 60(23): 12891-12896, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33829645

RESUMEN

Although a few semiconductors can directly absorb infrared light, their intrinsic properties like improper band-edge position and strong electron-hole interaction restrict further photocatalytic applications. Herein, we propose an exciton-mediated energy transfer strategy for realizing efficient infrared light response in heterostructures. Using black phosphorous/polymeric carbon nitride (BP/CN) heterojunction, CN could be indirectly excited by infrared light with the aid of nonradiatively exciton-based energy transfer from BP. At the same time, excitons are dissociated into free charge carriers at the interface of BP/CN heterojunction, followed by hole injection to BP and electron retainment in CN. As a result of these unique photoexcitation processes, BP/CN heterojunction exhibits promoted conversion rate and selectivity in amine-amine oxidative coupling reaction even under infrared light irradiation. This study opens a new way for the design of efficient infrared light activating photocatalysts.

14.
J Cell Mol Med ; 24(14): 7814-7828, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32445435

RESUMEN

Hepatic ischaemia/reperfusion (I/R) injury is a major clinical problem during liver surgical procedures, which usually lead to early transplantation failure and higher organ rejection rate, and current effective therapeutic strategies are still limited. Therefore, in-depth exploring of the molecular mechanisms underlying liver I/R injury is key to the development of new therapeutic methods. ß-arrestins are multifunctional proteins serving as important signalling scaffolds in numerous physiopathological processes, including liver-specific diseases. However, the role and underlying mechanism of ß-arrestins in hepatic I/R injury remain largely unknown. Here, we showed that only ARRB1, but not ARRB2, was down-regulated during liver I/R injury. Hepatocyte-specific overexpression of ARRB1 significantly ameliorated liver damage, as demonstrated by decreases in serum aminotransferases, hepatocellular necrosis and apoptosis, infiltrating inflammatory cells and secretion of pro-inflammatory cytokines relative to control mice, whereas experiments with ARRB1 knockout mice gotten opposite effects. Mechanistically, ARRB1 directly interacts with ASK1 in hepatocytes and inhibits its TRAF6-mediated Lysine 6-linked polyubiquitination, which then prevents the activation of ASK1 and its downstream signalling pathway during hepatic I/R injury. In addition, inhibition of ASK1 remarkably abolished the disruptive effect result from ARRB1 deficiency in liver I/R injury in vivo, indicating that ASK1 was required for ARRB1 function in hepatic I/R injury. In conclusion, we proposed that ARRB1 is a novel protective regulator during liver I/R injury, and modulation of the regulatory axis between ARRB1 and ASK1 could be a novel therapeutic strategy to prevent this pathological process.


Asunto(s)
Hepatopatías/etiología , Hepatopatías/metabolismo , MAP Quinasa Quinasa Quinasa 5/metabolismo , Daño por Reperfusión/etiología , Daño por Reperfusión/metabolismo , Factor 6 Asociado a Receptor de TNF/metabolismo , beta-Arrestina 1/genética , beta-Arrestina 1/metabolismo , Animales , Apoptosis , Citocinas/metabolismo , Modelos Animales de Enfermedad , Hepatocitos/metabolismo , Inmunohistoquímica , Mediadores de Inflamación/metabolismo , Hepatopatías/patología , Lisina/metabolismo , Sistema de Señalización de MAP Quinasas , Masculino , Ratones , Daño por Reperfusión/patología , Ubiquitinación
15.
J Hepatol ; 72(5): 976-989, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-31857195

RESUMEN

BACKGROUND & AIMS: Non-alcoholic steatohepatitis (NASH) is associated with the dysregulation of lipid metabolism and hepatic inflammation. The causal mechanism underlying NASH is not fully elucidated. This study investigated the role of ß-Arrestin1 (ARRB1) in the progression of NASH. METHODS: Liver tissue from patients with NASH and controls were obtained to evaluate ARRB1 expression. NASH models were established in Arrb1-knockout and wild-type mice fed either a high-fat diet (HFD) for 26 weeks or a methionine/choline-deficient (MCD) diet for 6 weeks. RESULTS: ARRB1 expression was reduced in liver samples from patients with NASH. Reduced Arrb1 levels were also detected in murine NASH models. Arrb1 deficiency accelerated steatohepatitis development in HFD-/MCD-fed mice (accompanied by the upregulation of lipogenic genes and downregulation of ß-oxidative genes). Intriguingly, ARRB1 was found to interact with growth differentiation factor 15 (GDF15) and facilitated the transportation of GDF15 precursor (pro-GDF15) to the Golgi apparatus for cleavage and maturation. Treatment with recombinant GDF15 ablated the lipid accumulation in the presence of Arrb1 deletion both in vitro and in vivo. Re-expression of Arrb1 in the NASH models ameliorated the liver disease, and this effect was greater in the presence of pro-GDF15 overexpression. By contrast, the effect of pro-GDF15 overexpression alone was impaired in Arrb1-deficient mice. In addition, the severity of liver disease in patients with NASH was negatively correlated with ARRB1 expression. CONCLUSION: ARRB1 acts as a vital regulator in the development of NASH by facilitating the translocation of GDF15 to the Golgi apparatus and its subsequent maturation. Thus, ARRB1 is a potential therapeutic target for the treatment of NASH. LAY SUMMARY: Non-alcoholic steatohepatitis (NASH) is associated with the progressive dysfunction of lipid metabolism and a consequent inflammatory response. Decreased ARRB1 is observed in patients with NASH and murine NASH models. Re-expression of Arrb1 in the murine NASH model ameliorated liver disease, an effect which was more pronounced in the presence of pro-GDF15 overexpression, highlighting a promising strategy for NASH therapy.


Asunto(s)
Progresión de la Enfermedad , Factor 15 de Diferenciación de Crecimiento/metabolismo , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Transducción de Señal/genética , beta-Arrestina 1/deficiencia , beta-Arrestina 1/metabolismo , Adulto , Animales , Deficiencia de Colina/complicaciones , Dieta Alta en Grasa/efectos adversos , Modelos Animales de Enfermedad , Femenino , Aparato de Golgi/metabolismo , Humanos , Lipogénesis/genética , Masculino , Metionina/deficiencia , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Persona de Mediana Edad , Enfermedad del Hígado Graso no Alcohólico/etiología , Enfermedad del Hígado Graso no Alcohólico/patología , Adulto Joven , beta-Arrestina 1/genética
16.
FASEB J ; 33(6): 7049-7060, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30840837

RESUMEN

Hepatic ischemia-reperfusion (I/R) injury is a major challenge in liver resection and transplantation surgeries. Previous studies have revealed that guanine nucleotide-binding protein G(i)α2 (GNAI2) was involved in the progression of myocardial and cerebral I/R injury, but the role and function of GNAI2 in hepatic I/R have not been elucidated. The hepatocyte-specific GNAI2 knockout (GNAI2hep-/-) mice were generated and subjected to hepatic I/R injury. Primary hepatocytes isolated from GNAI2hep-/- and GNAI2flox/flox mice were cultured and challenged to hypoxia-reoxygenation insult. The specific function of GNAI2 in I/R-triggered hepatic injury and the underlying molecular mechanism were explored by various phenotypic analyses and molecular biology methods. In this study, we demonstrated that hepatic GNAI2 expression was significantly increased in liver transplantation patients and wild-type mice after hepatic I/R. Interestingly, hepatocyte-specific GNAI2 deficiency attenuated I/R-induced liver damage, inflammation cytokine expression, macrophage/neutrophil infiltration, and hepatocyte apoptosis in vivo and in vitro. Mechanistically, up-regulation of GNAI2 phosphorylates mixed-lineage protein kinase 3 (MLK3) through direct binding, which exacerbated hepatic I/R damage via MAPK and NF-κB pathway activation. Furthermore, blocking MLK3 signaling reversed GNAI2-mediated hepatic I/R injury. Our study firstly identifies GNAI2 as a promising target for prevention of hepatic I/R-induced injury and related liver diseases.-Sun, Q., He, Q., Xu, J., Liu, Q., Lu, Y., Zhang, Z., Xu, X., Sun, B. Guanine nucleotide-binding protein G(i)α2 aggravates hepatic ischemia-reperfusion injury in mice by regulating MLK3 signaling.


Asunto(s)
Subunidad alfa de la Proteína de Unión al GTP Gi2/metabolismo , Hepatopatías/metabolismo , Quinasas Quinasa Quinasa PAM/metabolismo , Daño por Reperfusión/fisiopatología , Animales , Apoptosis , Células Cultivadas , Regulación hacia Abajo , Subunidad alfa de la Proteína de Unión al GTP Gi2/genética , Regulación de la Expresión Génica , Hepatocitos/metabolismo , MAP Quinasa Quinasa 4/genética , MAP Quinasa Quinasa 4/metabolismo , Quinasas Quinasa Quinasa PAM/genética , Sistema de Señalización de MAP Quinasas/fisiología , Ratones , Transducción de Señal , Proteina Quinasa Quinasa Quinasa 11 Activada por Mitógeno
17.
Neural Comput ; 32(1): 182-204, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31703174

RESUMEN

A spiking neural network (SNN) is a type of biological plausibility model that performs information processing based on spikes. Training a deep SNN effectively is challenging due to the nondifferention of spike signals. Recent advances have shown that high-performance SNNs can be obtained by converting convolutional neural networks (CNNs). However, the large-scale SNNs are poorly served by conventional architectures due to the dynamic nature of spiking neurons. In this letter, we propose a hardware architecture to enable efficient implementation of SNNs. All layers in the network are mapped on one chip so that the computation of different time steps can be done in parallel to reduce latency. We propose new spiking max-pooling method to reduce computation complexity. In addition, we apply approaches based on shift register and coarsely grained parallels to accelerate convolution operation. We also investigate the effect of different encoding methods on SNN accuracy. Finally, we validate the hardware architecture on the Xilinx Zynq ZCU102. The experimental results on the MNIST data set show that it can achieve an accuracy of 98.94% with eight-bit quantized weights. Furthermore, it achieves 164 frames per second (FPS) under 150 MHz clock frequency and obtains 41× speed-up compared to CPU implementation and 22 times lower power than GPU implementation.

18.
Nature ; 514(7522): 385-8, 2014 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-25252974

RESUMEN

Retinoblastoma is a childhood retinal tumour that initiates in response to biallelic RB1 inactivation and loss of functional retinoblastoma (Rb) protein. Although Rb has diverse tumour-suppressor functions and is inactivated in many cancers, germline RB1 mutations predispose to retinoblastoma far more strongly than to other malignancies. This tropism suggests that retinal cell-type-specific circuitry sensitizes to Rb loss, yet the nature of the circuitry and the cell type in which it operates have been unclear. Here we show that post-mitotic human cone precursors are uniquely sensitive to Rb depletion. Rb knockdown induced cone precursor proliferation in prospectively isolated populations and in intact retina. Proliferation followed the induction of E2F-regulated genes, and depended on factors having strong expression in maturing cone precursors and crucial roles in retinoblastoma cell proliferation, including MYCN and MDM2. Proliferation of Rb-depleted cones and retinoblastoma cells also depended on the Rb-related protein p107, SKP2, and a p27 downregulation associated with cone precursor maturation. Moreover, Rb-depleted cone precursors formed tumours in orthotopic xenografts with histological features and protein expression typical of human retinoblastoma. These findings provide a compelling molecular rationale for a cone precursor origin of retinoblastoma. More generally, they demonstrate that cell-type-specific circuitry can collaborate with an initiating oncogenic mutation to enable tumorigenesis.


Asunto(s)
Células Fotorreceptoras Retinianas Conos/metabolismo , Células Fotorreceptoras Retinianas Conos/patología , Proteína de Retinoblastoma/metabolismo , Retinoblastoma/metabolismo , Retinoblastoma/patología , Transformación Celular Neoplásica , Factores de Transcripción E2F/metabolismo , Regulación Neoplásica de la Expresión Génica , Genes de Retinoblastoma/genética , Xenoinjertos , Humanos , Proteína Proto-Oncogénica N-Myc , Proteínas Nucleares/metabolismo , Proteínas Oncogénicas/metabolismo , Especificidad de Órganos , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Retinoblastoma/genética , Proteína de Retinoblastoma/deficiencia , Proteína de Retinoblastoma/genética , Proteína p107 Similar a la del Retinoblastoma/metabolismo , Proteína p130 Similar a la del Retinoblastoma/deficiencia , Proteína p130 Similar a la del Retinoblastoma/metabolismo , Proteínas Quinasas Asociadas a Fase-S/metabolismo , Células Madre/metabolismo , Células Madre/patología
19.
J Am Chem Soc ; 141(1): 423-430, 2019 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-30537829

RESUMEN

The concurrent transformation of carbon dioxide and water into hydrocarbons and oxygen by low-photonic-energy IR light still represents a huge challenge. Here, we design an ultrathin conductor system, in which the special partially occupied band serves as the mediator to simultaneously guarantee IR light harvesting and satisfy band-edge positions, while the ultrathin configuration improves charge separation rates and surface redox kinetics. Taking the low cost and earth-abundant CuS as an example, we first fabricate ultrathin CuS layers, where temperature-dependent resistivities, valence-band spectra, and theoretical calculations affirm their metallic nature. Synchrotron-radiation photoelectron and ultraviolet-visible-near-infrared spectra show that metallic CuS atomic layers could realize a new cooperative intraband-interband transition under IR light irradiation, where the generated electrons and holes could simultaneously involve the carbon dioxide reduction and water oxidation reactions. As a result, CuS atomic layers exhibit nearly 100% selective CO production with an evolution rate of 14.5 µmol g-1 h-1 under IR light irradiation, while the catalytic performance shows no obvious decay after a 96 h test. Briefly, benefiting from ultrahigh conductivity and a unique partially occupied band, abundant conductor materials such as conducting metal sulfides and metal nitrides hold great promise for applications as effective IR light responsive photocatalysts.

20.
Hepatology ; 68(5): 1865-1878, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-29704239

RESUMEN

Cluster of differentiation 97 (CD97) is a member of the epidermal growth factor seven-transmembrane family belonging to the class B G protein-coupled receptors (GPCRs). The protein affects tumor aggressiveness through its cellular ligand CD55 stimulation and exhibits adhesive properties. Studies have demonstrated the involvement of CD97 in dedifferentiation, migration, invasiveness, and metastasis of tumors. However, little information is currently available on the specific role of CD97 in hepatocellular carcinoma (HCC). Here, we have shown that CD97 up-regulation in HCCs is positively correlated with tumor metastasis. Functionally, CD97 promoted cell migration and invasion in vitro. In an in vivo mouse model, overexpression of CD97 in HCC cells led to accelerated lung metastasis. Mechanistically, CD97 cooperated with the altered regulator, GPCR kinase 6 (GRK6), to mediate GPCR desensitization and internalization. Down-regulation of GRK6 suppressed CD97 internalization and promoted CD97 expression. Integrated regulatory interactions between CD97 and GRK6 stimulated downstream matrix metalloproteinase 2/9 secretion and, consequently, HCC metastasis. Conclusion: Our collective findings support the utility of CD97 as an effective potential prognosticator and therapeutic target for HCC.


Asunto(s)
Antígenos CD/metabolismo , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Animales , Carcinoma Hepatocelular/patología , Femenino , Quinasas de Receptores Acoplados a Proteína-G/metabolismo , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Neoplasias Hepáticas/patología , Masculino , Ratones , Persona de Mediana Edad , Pronóstico , Transducción de Señal , Análisis de Supervivencia
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