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1.
Nature ; 615(7950): 56-61, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36859579

RESUMEN

Correlating atomic configurations-specifically, degree of disorder (DOD)-of an amorphous solid with properties is a long-standing riddle in materials science and condensed matter physics, owing to difficulties in determining precise atomic positions in 3D structures1-5. To this end, 2D systems provide insight to the puzzle by allowing straightforward imaging of all atoms6,7. Direct imaging of amorphous monolayer carbon (AMC) grown by laser-assisted depositions has resolved atomic configurations, supporting the modern crystallite view of vitreous solids over random network theory8. Nevertheless, a causal link between atomic-scale structures and macroscopic properties remains elusive. Here we report facile tuning of DOD and electrical conductivity in AMC films by varying growth temperatures. Specifically, the pyrolysis threshold temperature is the key to growing variable-range-hopping conductive AMC with medium-range order (MRO), whereas increasing the temperature by 25 °C results in AMC losing MRO and becoming electrically insulating, with an increase in sheet resistance of 109 times. Beyond visualizing highly distorted nanocrystallites embedded in a continuous random network, atomic-resolution electron microscopy shows the absence/presence of MRO and temperature-dependent densities of nanocrystallites, two order parameters proposed to fully describe DOD. Numerical calculations establish the conductivity diagram as a function of these two parameters, directly linking microstructures to electrical properties. Our work represents an important step towards understanding the structure-property relationship of amorphous materials at the fundamental level and paves the way to electronic devices using 2D amorphous materials.

2.
Am J Physiol Gastrointest Liver Physiol ; 325(3): G213-G229, 2023 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-37366545

RESUMEN

The endocannabinoid system (ECS) is dysregulated in various liver diseases. Previously, we had shown that the major endocannabinoid 2-arachidonoyl glycerol (2-AG) promoted tumorigenesis of intrahepatic cholangiocarcinoma (ICC). However, biosynthesis regulation and clinical significance of 2-AG remain elusive. In the present study, we quantified 2-AG by gas chromatography/mass spectrometry (GC/MS) and showed that 2-AG was enriched in patients with ICC samples as well as in thioacetamide-induced orthotopic rat ICC model. Moreover, we found that diacylglycerol lipase ß (DAGLß) was the principal synthesizing enzyme of 2-AG that significantly upregulated in ICC. DAGLß promoted tumorigenesis and metastasis of ICC in vitro and in vivo and positively correlated with clinical stage and poor survival in patients with ICC. Functional studies showed that activator protein-1 (AP-1; heterodimers of c-Jun and FRA1) directly bound to the promoter and regulated transcription of DAGLß, which can be enhanced by lipopolysaccharide (LPS). miR-4516 was identified as the tumor-suppressing miRNA of ICC that can be significantly suppressed by LPS, 2-AG, or ectopic DAGLß overexpression. FRA1 and STAT3 were targets of miR-4516 and overexpression of miRNA-4516 significantly suppressed expression of FRA1, SATA3, and DAGLß. Expression of miRNA-4516 was negatively correlated with FRA1, SATA3, and DAGLß in patients with ICC samples. Our findings identify DAGLß as the principal synthesizing enzyme of 2-AG in ICC. DAGLß promotes oncogenesis and metastasis of ICC and is transcriptionally regulated by a novel AP-1/DAGLß/miR4516 feedforward circuitry.NEW & NOTEWORTHY Dysregulated endocannabinoid system (ECS) had been confirmed in various liver diseases. However, regulation and function of 2-arachidonoyl glycerol (2-AG) and diacylglycerol lipase ß (DAGLß) in intrahepatic cholangiocarcinoma (ICC) remain to be elucidated. Here, we demonstrated that 2-AG was enriched in ICC, and DAGLß was the principal synthesizing enzyme of 2-AG in ICC. DAGLß promotes tumorigenesis and metastasis in ICC via a novel activator protein-1 (AP-1)/DAGLß/miR4516 feedforward circuitry.


Asunto(s)
Neoplasias de los Conductos Biliares , Colangiocarcinoma , MicroARNs , Ratas , Animales , Factor de Transcripción AP-1/genética , Endocannabinoides , Lipoproteína Lipasa , Glicerol , Lipopolisacáridos , Colangiocarcinoma/patología , MicroARNs/genética , MicroARNs/metabolismo , Conductos Biliares Intrahepáticos/metabolismo , Conductos Biliares Intrahepáticos/patología , Neoplasias de los Conductos Biliares/metabolismo , Carcinogénesis , Línea Celular Tumoral
3.
Nano Lett ; 22(1): 73-80, 2022 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-34962398

RESUMEN

The Berry curvature and orbital magnetic moment (OMM) come from either inversion symmetry or time-reversal symmetry breaking in quantum materials. Here, we demonstrate the significance of OMMs and Berry curvature in planar Hall effect (PHE) in antiferromagnetic topological insulator MnBi2Te4 flakes. We observe a PHE with period of π and positive magnitude at low fields, resembling the PHE of the surface states in nonmagnetic topological insulators. Remarkably, a novel predominant PHE with period of π/2 and negative magnitude emerges below the Néel temperature with B > 10 T. Our theoretical calculations reveal that this unusual π/2-periodic PHE originates from the topological OMMs of bulk Dirac electrons. Moreover, the competition between the contributions from the bulk and the surface states leads to nontrivial evolutions of PHE and anisotropic magnetoresistance. Our results reveal intriguing electromagnetic response due to the OMMs and also provide insight into the potential applications of magnetic topological insulators in spintronics.

4.
Nano Lett ; 22(18): 7328-7335, 2022 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-36067249

RESUMEN

Here, using various substrates, we demonstrate that the in-plane uniaxial strain engineering can enhance the Jahn-Teller distortions and promote selective orbital occupancy to induce an emergent antiferromagnetic insulating (AFI) phase at x = 1/3 of La1-xCaxMnO3. Such an AFI phase depends not only on the magnitude of epitaxial strain but also on the symmetry of the substrates. Using the large uniaxial strain imparted by DyScO3(001) substrate, the AFI ground state is achieved in a wide range of doping levels (0 ≤ x ≤ 1/2), leaving an extended AFI phase diagram. Moreover, it is found that hydrostatic pressure can tune the AFI phase back to a hidden ferromagnetic metallic phase, accompanied by the formation of accommodation strain. The coaction of the accommodation strain, uniaxial strain, and hydrostatic pressure produces complex phase competition and evolution, and the result may shed light on phase space control of other functional perovskites with the competing magnetic interactions.

5.
Ecotoxicol Environ Saf ; 240: 113671, 2022 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-35653972

RESUMEN

With the wide application of static magnetic fields (SMFs), the risk of living organisms exposed to man-made magnetic fields that the intensity is much higher than geomagnetic field has gradually increased. Reproductive system is highly sensitive to environmental stress; however, the influence of high SMFs on reproduction system is still largely unknown. Here we explored the biological responses of SMFs exposure at an intensity of 10 T on the sperms and their offspring in him-5 male mutants of Caenorhabditis elegans (C. elegans). The size of unactivated sperms was deceased by 10 T SMF exposure, instead of the morphology. Exposure to 10 T SMF significantly altered the function of sperms in him-5 worms including the activation of sperms and the non-transferred ratio of sperms. In addition, the brood size assay revealed that 10 T SMF exposure eventually diminished the reproductive capacity of him-5 male worms. The lifespan of outcrossed offspring from exposed him-5 male mutants and unexposed fog-2 female mutants was decreased by 10 T SMF in a time dependent manner. Together, our findings provide novel information regarding the adverse effects of high SMFs on the sperms of C. elegans and their offspring, which can improve our understanding of the fundamental aspects of high SMFs on biological system.


Asunto(s)
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animales , Caenorhabditis elegans/genética , Femenino , Humanos , Longevidad , Campos Magnéticos , Masculino , Reproducción
6.
Int J Mol Sci ; 23(4)2022 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-35216366

RESUMEN

Adventitious roots (ARs) have an unmatched status in plant growth and metabolism due to the degeneration of primary roots in lotuses. In the present study, we sought to assess the effect of sucrose on ARs formation and observed that lignin synthesis was involved in ARs development. We found that the lignification degree of the ARs primordium was weaker in plants treated with 20 g/L sucrose than in 50 g/L sucrose treatment and control plants. The contents of lignin were lower in plants treated with 20 g/L sucrose and higher in plants treated with 50 g/L sucrose. The precursors of monomer lignin, including p-coumaric acid, caffeate, sinapinal aldehyde, and ferulic acid, were lower in the GL50 library than in the GL20 library. Further analysis revealed that the gene expression of these four metabolites had no novel difference in the GL50/GL20 libraries. However, a laccase17 gene (NnLAC17), involved in polymer lignin synthesis, had a higher expression in the GL50 library than in the GL20 library. Therefore, NnLAC17 was cloned and the overexpression of NnLAC17 was found to directly result in a decrease in the root number in transgenic Arabidopsis plants. These findings suggest that lignin synthesis is probably involved in ARs formation in lotus seedlings.


Asunto(s)
Arabidopsis/genética , Lignina/genética , Lotus/genética , Nelumbo/genética , Raíces de Plantas/genética , Plantones/genética , Sacarosa/metabolismo , Arabidopsis/metabolismo , Ácidos Cumáricos/metabolismo , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas/genética , Lignina/metabolismo , Lotus/metabolismo , Nelumbo/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raíces de Plantas/metabolismo , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , Metabolismo Secundario/genética , Plantones/metabolismo
7.
Am J Pathol ; 190(11): 2185-2193, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32919978

RESUMEN

Chronic alcohol consumption is linked to the development of alcohol-associated liver disease (ALD). This disease is characterized by a clinical spectrum ranging from steatosis to hepatocellular carcinoma. Several cell types are involved in ALD progression, including hepatic macrophages. Kupffer cells (KCs) are the resident macrophages of the liver involved in the progression of ALD by activating pathways that lead to the production of cytokines and chemokines. In addition, KCs are involved in the production of reactive oxygen species. Reactive oxygen species are linked to the induction of oxidative stress and inflammation in the liver. These events are activated by the bacterial endotoxin, lipopolysaccharide, that is released from the gastrointestinal tract through the portal vein to the liver. Lipopolysaccharide is recognized by receptors on KCs that are responsible for triggering several pathways that activate proinflammatory cytokines involved in alcohol-induced liver injury. In addition, KCs activate hepatic stellate cells that are involved in liver fibrosis. Novel strategies to treat ALD aim at targeting Kupffer cells. These interventions modulate Kupffer cell activation or macrophage polarization. Evidence from mouse models and early clinical studies in patients with ALD injury supports the notion that pathogenic macrophage subsets can be successfully translated into novel treatment options for patients with this disease.


Asunto(s)
Comunicación Celular , Células Estrelladas Hepáticas/metabolismo , Macrófagos del Hígado/metabolismo , Hepatopatías Alcohólicas/metabolismo , Hígado/metabolismo , Animales , Quimiocinas/metabolismo , Modelos Animales de Enfermedad , Células Estrelladas Hepáticas/patología , Humanos , Macrófagos del Hígado/patología , Hígado/patología , Hepatopatías Alcohólicas/patología , Ratones , Especies Reactivas de Oxígeno/metabolismo
8.
Carcinogenesis ; 40(9): 1055-1060, 2019 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-30874286

RESUMEN

Global DNA methylation may play important roles in cancer etiology and prognosis. The goal of this study is to investigate whether the methylation of long interspersed nucleotide elements (LINE-1) and subtelomeric DNA repeats D4Z4 in leukocyte DNA is associated with aggressive prostate cancer (PCa) in African Americans. We measured DNA methylation levels of LINE-1 and D4Z4 in 306 African American (AA) PCa patients using pyrosequencing and compared their methylation levels among clinical variables. We further applied multivariate Cox proportional hazards model and Kaplan-Meier survival function and log-rank tests to assess the association between DNA methylation and biochemical recurrence (BCR). Overall, there was no significant difference of the methylation levels of LINE-1 and D4Z4 among patients with different clinical and epidemiological characteristics. However, the methylation of LINE-1 and D4Z4 was associated with BCR. Patients with lower LINE-1 methylation and higher D4Z4 methylation exhibited markedly increased risks of BCR with adjusted hazard ratios of 3.34 (95% confidence interval, 1.32-8.45) and 4.12 (95% confidence interval, 1.32-12.86), respectively, and significantly shorter BCR-free survival times. Our results suggest that lower global DNA methylation and higher subtelomeric region methylation may predict worse prognosis in localized AA PCa patients.

9.
FASEB J ; 31(10): 4305-4324, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28634212

RESUMEN

Melatonin therapy or prolonged exposure to complete darkness reduces biliary hyperplasia and liver fibrosis in bile-duct-ligated (BDL) rats; however, no information exists in primary sclerosing cholangitis (PSC). Thus, we aimed to determine the therapeutic effects of prolonged dark therapy or melatonin administration on hepatic fibrosis in the multidrug resistance gene 2-knockout (Mdr2-/-) mouse model of PSC. Melatonin levels, biliary mass, liver fibrosis, angiogenesis and miR-200b expression were evaluated in wild-type and Mdr2-/- mice exposed to darkness or melatonin treatment or in male patients with PSC and healthy controls. Mdr2-/- mice were also treated with miR-200b inhibitor or control before evaluating biliary mass, liver fibrosis, and angiogenesis. After overexpression of arylalkylamine N-acetyltransferase (AANAT; the enzyme regulating melatonin synthesis) or inhibition of miR-200b in cholangiocytes and hepatic stellate cells in vitro, we evaluated angiogenesis and fibrosis gene expression. After exposure to darkness or administration of melatonin, Mdr2-/- mice show elevated serum melatonin levels and inhibition of biliary mass, along with reduction of liver fibrosis and angiogenesis. MicroRNA PCR analysis demonstrated that miR-200b expression increased in Mdr2-/- mice and patients with PSC compared with controls and decreased in Mdr2-/- mice subjected to dark exposure or melatonin treatment. Inhibition of miR-200b in Mdr2-/- ablates biliary proliferation, liver fibrosis, and angiogenesis. In vitro, overexpression of AANAT or inhibition of miR-200b in cholangiocytes and hepatic stellate cells decreased the expression of miR-200b, angiogenesis, and fibrosis genes. Dark therapy or targeting melatonin/miR-200b axis may be important in the management of biliary damage and liver fibrosis in cholangiopathies including PSC.-Wu, N., Meng, F., Zhou, T., Han, Y., Kennedy, L., Venter, J., Francis, H., DeMorrow, S., Onori, P., Invernizzi, P., Bernuzzi, F., Mancinelli, R., Gaudio, E., Franchitto, A., Glaser, S., Alpini G. Prolonged darkness reduces liver fibrosis in a mouse model of primary sclerosing cholangitis by miR-200b down-regulation.


Asunto(s)
Colangitis Esclerosante/metabolismo , Oscuridad , Células Estrelladas Hepáticas/metabolismo , Cirrosis Hepática/metabolismo , Melatonina/metabolismo , MicroARNs/genética , Inductores de la Angiogénesis/metabolismo , Animales , Proliferación Celular/fisiología , Colangitis Esclerosante/genética , Modelos Animales de Enfermedad , Regulación hacia Abajo , Fibrosis/metabolismo , Masculino , Ratones Transgénicos
10.
Carcinogenesis ; 38(8): 821-826, 2017 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-28854562

RESUMEN

Global DNA methylation may affect chromosome structure and genomic stability and is involved in carcinogenesis. In this study, we aimed to investigate whether methylation of pericentromeric repeat NBL2 and subtelomeric repeat D4Z4 in peripheral blood was associated with the aggressiveness of prostate cancer (PCa). We measured the methylation status of different CpG sites of NBL2 and D4Z4 in 795 PCa patients and compared their methylation levels among patients with different Gleason Score at diagnosis. We then analyzed the association of the NBL2 and D4Z4 methylation with the risk of biochemical recurrence (BCR) in patients receiving radical prostatectomy or radiotherapy using a multivariate Cox proportional hazards model. In addition, we used the Kaplan-Meier survival function and log-rank tests to assess BCR-free survival associated with D4Z4 methylation. There was no significant difference in methylation level of NBL2 and D4Z4 between clinically defined aggressive and non-aggressive PCa at diagnosis. However, the methylation of D4Z4 was associated with BCR, while the methylation of NBL2 was not. In tertile analysis, patients in the highest tertile of D4Z4 methylation had an increased risk of BCR (HR = 2.17, 95% CI 1.36-3.48) compared to patients in the lower tertiles after adjustment of age, body mass index, smoking status, pack year, D'Amico risk groups and treatments. Among the four CpG sites in this region, the association was mostly attributable to the methylation of the second CpG site of D4Z4. These data suggest that higher methylation in D4Z4 was associated with worse prognosis of localized PCa patients.


Asunto(s)
Biomarcadores de Tumor/sangre , Metilación de ADN/genética , Recurrencia Local de Neoplasia/sangre , Neoplasias de la Próstata/sangre , Anciano , Supervivencia sin Enfermedad , Humanos , Estimación de Kaplan-Meier , Leucocitos/patología , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/patología , Prostatectomía , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/cirugía , Secuencias Repetidas en Tándem/genética , Telómero/genética
11.
Am J Pathol ; 186(1): 123-33, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26597881

RESUMEN

The tumor microenvironment of cholangiocarcinoma (CCA) is composed of numerous cells, including mast cells (MCs). MCs release histamine, which increases CCA progression and angiogenesis. Cholangiocytes secrete stem cell factor, which functions via the MC growth factor receptor c-Kit. Here, we show that cholangiocytes express histidine decarboxylase and its inhibition reduces CCA growth. MC recruitment in the tumor microenvironment increased CCA growth. MC infiltration and MC markers were detected by toluidine blue staining and real-time PCR in human biopsies and in tumors from athymic mice treated with saline, histamine, histidine decarboxylase inhibitor, or cromolyn sodium. Tumor growth, angiogenesis, and epithelial-mesenchymal transition (EMT)/extracellular matrix (ECM) markers were measured in mice treated with cromolyn sodium. In vitro, human CCA cells were treated with MC supernatant fluids before evaluating angiogenesis and EMT/ECM expression. Migration assays were performed with CCA cells treated with the stem cell factor inhibitor. MC supernatant fluids increased CCA histidine decarboxylase, vascular endothelial growth factor, and MC/EMT/ECM expression that decreased with pretreatment of cromolyn sodium. MCs were found in human biopsies. In mice treated with cromolyn sodium, MC infiltration and tumor growth decreased. Inhibition of CCA stem cell factor blocked MC migration and MC/EMT/ECM in CCA. MCs migrate into CCA tumor microenvironment via c-Kit/stem cell factor and increase tumor progression, angiogenesis, EMT switch, and ECM degradation.


Asunto(s)
Neoplasias de los Conductos Biliares/patología , Colangiocarcinoma/patología , Histamina/metabolismo , Mastocitos/metabolismo , Microambiente Tumoral/inmunología , Animales , Neoplasias de los Conductos Biliares/inmunología , Diferenciación Celular/inmunología , Proliferación Celular , Colangiocarcinoma/inmunología , Transición Epitelial-Mesenquimal/inmunología , Técnica del Anticuerpo Fluorescente , Xenoinjertos , Humanos , Inmunohistoquímica , Mastocitos/citología , Ratones , Ratones Desnudos , Neovascularización Patológica/inmunología , Neovascularización Patológica/patología , Proteínas Proto-Oncogénicas c-kit/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Transducción de Señal/fisiología , Factor de Células Madre/metabolismo , Análisis de Matrices Tisulares
12.
J Cell Mol Med ; 20(2): 195-203, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26645107

RESUMEN

Diabetes mellitus is one of the most severe endocrine metabolic disorders in the world that has serious medical consequences with substantial impacts on the quality of life. Type 2 diabetes is one of the main causes of diabetic liver diseases with the most common being non-alcoholic fatty liver disease. Several factors that may explain the mechanisms related to pathological and functional changes of diabetic liver injury include: insulin resistance, oxidative stress and endoplasmic reticulum stress. The realization that these factors are important in hepatocyte damage and lack of donor livers has led to studies concentrating on the role of stem cells (SCs) in the prevention and treatment of liver injury. Possible avenues that the application of SCs may improve liver injury include but are not limited to: the ability to differentiate into pancreatic ß-cells (insulin producing cells), the contribution for hepatocyte regeneration, regulation of lipogenesis, glucogenesis and anti-inflammatory actions. Once further studies are performed to explore the underlying protective mechanisms of SCs and the advantages and disadvantages of its application, there will be a greater understand of the mechanism and therapeutic potential. In this review, we summarize the findings regarding the role of SCs in diabetic liver diseases.


Asunto(s)
Complicaciones de la Diabetes/fisiopatología , Diabetes Mellitus Tipo 2/fisiopatología , Hepatopatías/fisiopatología , Células Madre/fisiología , Animales , Hepatocitos/fisiología , Humanos , Resistencia a la Insulina/fisiología , Hígado/fisiopatología
13.
J Hepatol ; 64(6): 1295-304, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-26923637

RESUMEN

BACKGROUND & AIMS: Disruption of circadian rhythm is associated with cancer development and progression. MicroRNAs (miRNAs) are a class of small non-coding RNAs that trigger mRNA translation inhibition. We aimed to evaluate the role of Per1 and related miRNAs in cholangiocarcinoma growth. METHODS: The expression of clock genes was evaluated in human cholangiocarcinoma tissue arrays and cholangiocarcinoma lines. The rhythmic expression of clock genes was evaluated in cholangiocarcinoma cells and H69 (non-malignant cholangiocytes) by qPCR. We measured cell proliferation, cell cycle and apoptosis in Mz-ChA-1 cells after Per1 overexpression. We examined tumor growth in vivo after injection of Per1 overexpressing cells. We verified miRNAs that targets Per1. The circadian rhythm of miR-34a was evaluated in cholangiocarcinoma and H69 cells. We evaluated cell proliferation, apoptosis and invasion after inhibition of miR-34a in vitro, and the potential molecular mechanisms by mRNA profiling after overexpression of Per1. RESULTS: Expression of Per1 was decreased in cholangiocarcinoma. The circadian rhythm of Per1 expression was lost in cholangiocarcinoma cells. Decreased cell proliferation, lower G2/M arrest, and enhanced apoptosis were shown in Per1 overexpressing cells. An in vivo study revealed decreased tumor growth, decreased proliferation, angiogenesis and metastasis after overexpressing Per1. Per1 was verified as a target of miR-34a. miR-34a was rhythmically expressed in cholangiocarcinoma cells and H69. The inhibition of miR-34a decreased proliferation, migration and invasion in cholangiocarcinoma cells. mRNA profiling has shown that overexpression of Per1 inhibits cell growth through regulation of multiple cancer-related pathways, such as cell cycle, cell growth and apoptosis pathways. CONCLUSIONS: Disruption of circadian rhythms of clock genes contribute to the malignant phenotypes of human cholangiocarcinoma. LAY SUMMARY: The current study is about how biological clock and its regulators affect the bile duct tumor growth. The disruption of biological clock has a negative impact in different cancers. Per1 is a gene that is involved in maintaining the biological clock and show 24h oscillation. Reduced levels of Per1 and disruption of 24h circadian rhythm was found in bile duct cancer cells. Therefore, a genetic modified bile duct cancer cells was created. It has a higher level of Per1 expression and partially recovered circadian rhythm. Those genetic modified cells also displayed slower cell growth or higher rate of cell death. We also used mice model that lack of immune system to show that our genetic modified bile duct cells form smaller tumor. In addition, we tried to see how Per1 is communicating with other genes in regarding of controlling the tumor growth. We found Per1 is regulated by microRNA-34a, a small non-coding RNA that directly binds to genes and inhibit gene expression. Decreased level of miR-34a has also significantly reduced tumor growth through controlling the cell growth and cell death balance. Therefore bile duct cancer patients may be treated with miR-34a inhibitor or Per1 stimulator in the future.


Asunto(s)
Neoplasias de los Conductos Biliares/patología , Colangiocarcinoma/patología , MicroARNs/fisiología , Proteínas Circadianas Period/fisiología , Animales , Proteínas CLOCK/genética , Línea Celular Tumoral , Proliferación Celular , Ritmo Circadiano , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Invasividad Neoplásica
14.
Am J Pathol ; 185(3): 602-9, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25619959

RESUMEN

Cellular senescence is a state of irreversible cell cycle arrest that has been involved in many gastrointestinal diseases, including human cholestatic liver disorders. Senescence may play a role in biliary atresia, primary sclerosing cholangitis, cellular rejection, and primary biliary cirrhosis, four liver diseases affecting cholangiocytes and the biliary system. In this review, we examine proposed mechanisms of senescence-related biliary diseases, including hypotheses associated with the senescence-associated phenotype, induction of senescence in nearby cells, and the depletion of stem cell subpopulations. Current evidence for the molecular mechanisms of senescence in the previously mentioned diseases is discussed in detail, with attention to recent advances on the role of pathways associated with senescence-associated phenotype, stress-induced senescence, telomere dysfunction, and autophagy.


Asunto(s)
Atresia Biliar/patología , Senescencia Celular , Colangitis Esclerosante/patología , Cirrosis Hepática Biliar/patología , Autofagia , Ciclo Celular , Humanos
15.
Am J Pathol ; 185(4): 1061-72, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25794706

RESUMEN

During cholestatic liver disease, there is dysregulation in the balance between biliary growth and loss in bile duct-ligated (BDL) rats modulated by neuroendocrine peptides via autocrine/paracrine pathways. Gonadotropin-releasing hormone (GnRH) is a trophic peptide hormone that modulates reproductive function and proliferation in many cell types. We evaluated the autocrine role of GnRH in the regulation of cholangiocyte proliferation. The expression of GnRH receptors was assessed in a normal mouse cholangiocyte cell line (NMC), sham, and BDL rats. The effect of GnRH administration was evaluated in normal rats and in NMC. GnRH-induced biliary proliferation was evaluated by changes in intrahepatic bile duct mass and the expression of proliferation and function markers. The expression and secretion of GnRH in NMC and isolated cholangiocytes was assessed. GnRH receptor subtypes GnRHR1 and GnRHR2 were expressed in cholangiocytes. Treatment with GnRH increased intrahepatic bile duct mass as well as proliferation and function markers in cholangiocytes. Transient knockdown and pharmacologic inhibition of GnRHR1 in NMC decreased proliferation. BDL cholangiocytes had increased expression of GnRH compared with normal rats, accompanied by increased GnRH secretion. In vivo and in vitro knockdown of GnRH decreased intrahepatic bile duct mass/cholangiocyte proliferation and fibrosis. GnRH secreted by cholangiocytes promotes biliary proliferation via an autocrine pathway. Disruption of GnRH/GnRHR signaling may be important for the management of cholestatic liver diseases.


Asunto(s)
Comunicación Autocrina , Conductos Biliares Intrahepáticos/citología , Hormona Liberadora de Gonadotropina/metabolismo , Comunicación Paracrina , Animales , Conductos Biliares Intrahepáticos/efectos de los fármacos , Línea Celular , Proliferación Celular/efectos de los fármacos , AMP Cíclico/metabolismo , Técnica del Anticuerpo Fluorescente , Silenciador del Gen/efectos de los fármacos , Hipotálamo/metabolismo , Inositol 1,4,5-Trifosfato/metabolismo , Cirrosis Hepática/patología , Masculino , Ratones , Morfolinos/administración & dosificación , Morfolinos/farmacología , Comunicación Paracrina/efectos de los fármacos , Ratas Endogámicas F344 , Receptores LHRH/metabolismo
16.
Nano Lett ; 15(2): 869-75, 2015 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-25575045

RESUMEN

Superconductor-insulator transition (SIT) in one-dimensional (1D) nanowires attracts great attention in the past decade and remains an open question since contrasting results were reported in nanowires with different morphologies (i.e., granular, polycrystalline, or amorphous) or environments. Nb2PdS5 is a recently discovered low-dimensional superconductor with typical quasi-1D chain structure. By decreasing the wire diameter in the range of 100-300 nm, we observed a clear SIT with a 1D transport character driven by both the cross-sectional area and external magnetic field. We also found that the upper critical magnetic field (Hc2) decreases with the reduction of nanowire cross-sectional area. The temperature dependence of the resistance below Tc can be described by the thermally activated phase slip (TAPS) theory without any signature of quantum phase slips (QPS). These findings demonstrated that the enhanced Coulomb interactions with the shrinkage of the wire diameter competes with the interchain Josephson-like coupling may play a crucial role on the SIT in quasi-1D system.

17.
J Biol Chem ; 289(40): 27526-39, 2014 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-25118289

RESUMEN

IL-6/Stat3 is associated with the regulation of transcription of key cellular regulatory genes (microRNAs) during different types of liver injury. This study evaluated the role of IL-6/Stat3 in regulating miRNA and miR-21 in alcoholic liver disease. By microarray, we identified that ethanol feeding significantly up-regulated 0.8% of known microRNAs in mouse liver compared with controls, including miR-21. Similarly, the treatment of normal human hepatocytes (N-Heps) and hepatic stellate cells (HSCs) with ethanol and IL-6 significantly increased miR-21 expression. Overexpression of miR-21 decreased ethanol-induced apoptosis in both N-Heps and HSCs. The expression level of miR-21 was significantly increased after Stat3 activation in N-Heps and HSCs, in support of the concept that the 5'-promoter region of miR-21 is regulated by Stat3. Using real time PCR, we confirmed that miR-21 activation is associated with ethanol-linked Stat3 binding of the miR-21 promoter. A combination of bioinformatics, PCR array, dual-luciferase reporter assay, and Western blot analysis revealed that Fas ligand (TNF superfamily, member 6) (FASLG) and death receptor 5 (DR5) are the direct targets of miR-21. Furthermore, inhibition of miR-21 by specific Vivo-Morpholino and knock-out of IL-6 in ethanol-treated mice also increased the expression of DR5 and FASLG in vivo during alcoholic liver injury. The identification of miR-21 as an important regulator of hepatic cell survival, transformation, and remodeling in vitro, as well as its upstream modulators and downstream targets, will provide insight into the involvement of altered miRNA expression in contributing to alcoholic liver disease progression and testing novel therapeutic approaches for human alcoholic liver diseases.


Asunto(s)
Apoptosis , Hepatopatías Alcohólicas/metabolismo , Hepatopatías Alcohólicas/fisiopatología , MicroARNs/metabolismo , Animales , Células Estrelladas Hepáticas/citología , Células Estrelladas Hepáticas/metabolismo , Humanos , Interleucina-6/genética , Interleucina-6/metabolismo , Hígado/citología , Hígado/metabolismo , Hepatopatías Alcohólicas/genética , Ratones , Ratones Endogámicos C57BL , MicroARNs/genética , Factor de Transcripción STAT3/genética , Factor de Transcripción STAT3/metabolismo , Transducción de Señal , Regulación hacia Arriba
18.
Gastroenterology ; 146(7): 1795-808.e12, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24583060

RESUMEN

BACKGROUND & AIMS: Proliferating cholangiocytes secrete and respond to neuroendocrine hormones, including secretin. We investigated whether secretin secreted by S cells and cholangiocytes stimulates biliary proliferation in mice. METHODS: Cholestasis was induced in secretin knockout (Sct(-/-)) and wild-type (control) mice by bile duct ligation (BDL). At days 3 and 7 after BDL, control and Sct(-/-) mice received tail-vein injections of morpholinos against microRNA 125b or let7a. One week later, liver tissues and cholangiocytes were collected. Immunohistochemical, immunoblot, luciferase reporter, and real-time polymerase chain reaction assays were performed. Intrahepatic bile duct mass (IBDM) and proliferation were measured. Secretin secretion was measured in conditioned media from cholangiocytes and S cells and in serum and bile. RESULTS: Secretin secretion was increased in supernatants from cholangiocytes and S cells and in serum and bile after BDL in control mice. BDL Sct(-/-) mice had lower IBDM, reduced proliferation, and reduced production of vascular endothelial growth factor (VEGF) A and nerve growth factor (NGF) compared with BDL control. BDL and control mice given morpholinos against microRNA 125b or let7a had increased IBDM. Livers of mice given morpholinos against microRNA 125b had increased expression of VEGFA, and those treated with morpholinos against microRNA let7a had increased expression of NGF. Secretin regulated VEGF and NGF expression that negatively correlated with microRNA 125b and let7a levels in liver tissue. CONCLUSIONS: After liver injury, secretin produced by cholangiocytes and S cells reduces microRNA 125b and let7a levels, resulting in up-regulation of VEGF and NGF. Modulation of cholangiocyte expression of secretin could be a therapeutic approach for biliary diseases.


Asunto(s)
Conductos Biliares/metabolismo , Proliferación Celular , Colestasis/metabolismo , Hígado/metabolismo , MicroARNs/metabolismo , Secretina/metabolismo , Animales , Apoptosis , Bilis/metabolismo , Conductos Biliares/patología , Células Cultivadas , Colestasis/genética , Colestasis/patología , Medios de Cultivo Condicionados/metabolismo , Modelos Animales de Enfermedad , Células Enteroendocrinas/metabolismo , Hígado/patología , Masculino , Ratones , Ratones Noqueados , MicroARNs/genética , Morfolinos/administración & dosificación , Factor de Crecimiento Nervioso/metabolismo , Secretina/sangre , Secretina/deficiencia , Secretina/genética , Transducción de Señal , Factores de Tiempo , Transfección , Factor A de Crecimiento Endotelial Vascular/metabolismo
19.
Am J Pathol ; 184(3): 662-73, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24384130

RESUMEN

Histamine is formed by the conversion of l-histidine into histamine by histidine decarboxylase (HDC). We have previously shown that inhibition of HDC blocks cholangiocyte proliferation and silencing of HDC decreases vascular endothelial growth factor (VEGF) expression. We hypothesized that increased HDC expression during cholestatic liver injury is mediated by the down-regulation of the specific miRNA miR-125b, a post-transcriptional regulator. Mice were subjected to sham surgery or bile duct ligation (BDL), which induces large cholangiocyte proliferation, and subsequently treated with either saline or α-methyl-dl-histidine (an HDC inhibitor) for 7 days. Liver blocks, serum, and large cholangiocytes were obtained, and intrahepatic bile duct mass, cholangiocyte proliferation (proliferating cellular nuclear antigen expression), and expression of both HDC and VEGF were measured. miRNA profiling was performed in isolated cholangiocytes. In vitro, miR-125b was overexpressed (or inhibited) or HDC was silenced before measuring HDC and VEGF-A/C expression and cholangiocyte proliferation. After BDL plus α-methyl-dl-histidine, expression of intrahepatic bile duct mass, proliferating cellular nuclear antigen, VEGF-A/C, and HDC and levels of histamine all decreased compared with those of BDL alone. miR-125b was significantly down-regulated after BDL. In vitro, overexpression of miR-125b and knockdown of HDC both decreased HDC and VEGF expression and cholangiocyte proliferation. Manipulation of miR-125b-regulated HDC/VEGF expression may, thus, be a therapeutic approach for the treatment of aberrant cholangiocyte growth in biliary disorders.


Asunto(s)
Colestasis/patología , Regulación de la Expresión Génica , Histamina/metabolismo , MicroARNs/genética , Factor A de Crecimiento Endotelial Vascular/metabolismo , Animales , Conductos Biliares Intrahepáticos/patología , Línea Celular , Proliferación Celular , Regulación hacia Abajo , Humanos , Hiperplasia/patología , Hígado/patología , Ratones
20.
Dig Dis Sci ; 60(5): 1273-83, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25487191

RESUMEN

BACKGROUND: Biliary tract cancers encompass gallbladder carcinoma, and intrahepatic, perihilar and distal cholangiocarcinoma. Upregulated serum CYFRA 21-1 has been reported in intrahepatic cholangiocarcinoma. AIMS: The present study aimed to explore the clinical significance of serum CYFRA 21-1 in all biliary tract cancer subtypes. METHODS: Serum CYFRA 21-1, carbohydrate antigen 19-9 and carcinoembryonic antigen were quantitated preoperatively, postoperatively and during follow-up in 134 malignant and 52 benign patients. Receiver operator characteristic curves of biomarkers were analyzed. Level of CYFRA 21-1 was correlated with patients' clinicopathological features and follow-up data. RESULTS: CYFRA 21-1 was significantly upregulated in biliary malignancies, and expressional difference existed between these subtypes. Based on the maximal Youden's index, cutoff values were selected (ng/mL): 2.61 for biliary tract cancers (sensitivity 74.6 % and specificity 84.6 %); 3.27 for intrahepatic cholangiocarcinoma (75.6 and 96.2 %) and gallbladder carcinoma (93.7 and 96.2 %); 2.27 for perihilar cholangiocarcinoma (71.0 and 71.2 %); and 2.61 for distal cholangiocarcinoma (63.3 and 84.6 %). CYFRA 21-1 showed better diagnostic performance than other biomarkers in gallbladder carcinoma and intrahepatic cholangiocarcinoma; its performance was not inferior to that of the combination of these three biomarkers and declined after curative resection and re-elevated when tumor recurred, which was correlated with tumor aggressiveness and TNM stage; it was an independent predictor for 1-year recurrence-free survival and overall survival on multivariate analysis. CONCLUSION: Serum CYFRA 21-1 represents a reliable biomarker for gallbladder carcinoma and intrahepatic cholangiocarcinoma.


Asunto(s)
Antígenos de Neoplasias/sangre , Neoplasias de los Conductos Biliares/sangre , Biomarcadores de Tumor/sangre , Colangiocarcinoma/sangre , Neoplasias de la Vesícula Biliar/sangre , Queratina-19/sangre , Adulto , Anciano , Anciano de 80 o más Años , Área Bajo la Curva , Neoplasias de los Conductos Biliares/mortalidad , Neoplasias de los Conductos Biliares/patología , Neoplasias de los Conductos Biliares/cirugía , Conductos Biliares Intrahepáticos/patología , Conductos Biliares Intrahepáticos/cirugía , Antígeno CA-19-9/sangre , Antígeno Carcinoembrionario/sangre , Distribución de Chi-Cuadrado , Colangiocarcinoma/mortalidad , Colangiocarcinoma/patología , Colangiocarcinoma/cirugía , Supervivencia sin Enfermedad , Femenino , Neoplasias de la Vesícula Biliar/mortalidad , Neoplasias de la Vesícula Biliar/patología , Neoplasias de la Vesícula Biliar/cirugía , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Análisis Multivariante , Estadificación de Neoplasias , Oportunidad Relativa , Valor Predictivo de las Pruebas , Modelos de Riesgos Proporcionales , Curva ROC , Reproducibilidad de los Resultados , Estudios Retrospectivos , Factores de Riesgo , Factores de Tiempo , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Regulación hacia Arriba
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