Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 29
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Trop Med Health ; 51(1): 44, 2023 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-37559114

RESUMEN

Nipah virus (NiV) is a zoonotic, single-stranded RNA virus from the family Paramyxoviridae, genus Henipavirus. NiV is a biosafety-level-4 pathogen that is mostly spread by Pteropus species, which serve as its natural reservoir host. NiV is one of the major public health challenges in South and South East Asia. However, few molecular studies have been conducted to characterise NiV in a specific region. The main objective of this review is to understand the epidemiology, pathogenesis, molecular surveillance, transmission dynamics, genetic diversity, reservoir host, clinical characteristics, and phylogenetics of NiV. South and South East Asian nations have experienced NiV outbreaks. Phylogenetic analysis confirmed that two primary clades of NiV are in circulation. In humans, NiV causes severe respiratory illness and/or deadly encephalitis. NiV is mainly diagnosed by ELISA along with PCR. Therefore, we recommend that the governments of the region support the One Health approach to reducing the risk of zoonotic disease transmission in their respective countries.

3.
JCI Insight ; 7(16)2022 08 22.
Artículo en Inglés | MEDLINE | ID: mdl-35852858

RESUMEN

Metastatic urothelial carcinoma is generally incurable with current systemic therapies. Chromatin modifiers are frequently mutated in bladder cancer, with ARID1A-inactivating mutations present in about 20% of tumors. EZH2, a histone methyltransferase, acts as an oncogene that functionally opposes ARID1A. In addition, PI3K signaling is activated in more than 20% of bladder cancers. Using a combination of in vitro and in vivo data, including patient-derived xenografts, we show that ARID1A-mutant tumors were more sensitive to EZH2 inhibition than ARID1A WT tumors. Mechanistic studies revealed that (a) ARID1A deficiency results in a dependency on PI3K/AKT/mTOR signaling via upregulation of a noncanonical PI3K regulatory subunit, PIK3R3, and downregulation of MAPK signaling and (b) EZH2 inhibitor sensitivity is due to upregulation of PIK3IP1, a protein inhibitor of PI3K signaling. We show that PIK3IP1 inhibited PI3K signaling by inducing proteasomal degradation of PIK3R3. Furthermore, ARID1A-deficient bladder cancer was sensitive to combination therapies with EZH2 and PI3K inhibitors in a synergistic manner. Thus, our studies suggest that bladder cancers with ARID1A mutations can be treated with inhibitors of EZH2 and/or PI3K and revealed mechanistic insights into the role of noncanonical PI3K constituents in bladder cancer biology.


Asunto(s)
Carcinoma de Células Transicionales , Proteínas de Unión al ADN/genética , Factores de Transcripción/genética , Neoplasias de la Vejiga Urinaria , Proteínas de Unión al ADN/metabolismo , Proteína Potenciadora del Homólogo Zeste 2/genética , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Humanos , Proteínas Nucleares/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Inhibidores de las Quinasa Fosfoinosítidos-3 , Transducción de Señal , Factores de Transcripción/metabolismo , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Neoplasias de la Vejiga Urinaria/genética
4.
Am J Respir Cell Mol Biol ; 66(2): 183-195, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34706199

RESUMEN

TLR4 signaling via endotoxemia in macrophages promotes macrophage transition to the inflammatory phenotype through NLRP3 inflammasome activation. This transition event has the potential to trigger acute lung injury (ALI). However, relatively little is known about the regulation of NLRP3 and its role in the pathogenesis of ALI. Here we interrogated the signaling pathway activated by CD38, an ectoenzyme expressed in macrophages, in preventing ALI through suppressing NLRP3 activation. Wild-type and Cd38-knockout (Cd38-/-) mice were used to assess inflammatory lung injury, and isolated macrophages were used to delineate underlying TLR4 signaling pathway. We showed that CD38 suppressed TLR4 signaling in macrophages by inhibiting Bruton's tyrosine kinase (Btk) through the recruitment of Src homology-2 domain containing protein tyrosine phosphatase-2 (SHP2) and resulting in the dephosphorylation of activated Btk. Cd38-/- mice show enhanced lung polymorphonuclear leukocyte extravasation and severe lung injury. LPS- or polymicrobial sepsis-induced mortality in Cd38-/- mice were markedly augmented compared with wild types. CD38 in macrophages functioned by inhibiting Btk activation through activation of SHP2 and resulting dephosphorylation of Btk, and thereby preventing activation of downstream targets NF-κB and NLRP3. Cd38-/- macrophages displayed markedly increased activation of Btk, NF-κB, and NLRP3, whereas in vivo administration of the Btk inhibitor ibrutinib (a Food and Drug Administration-approved drug) prevented augmented TLR4-induced inflammatory lung injury seen in Cd38-/- mice. Our findings together show upregulation of CD38 activity and inhibition of Btk activation downstream of TLR4 activation as potential strategies to prevent endotoxemic ALI.


Asunto(s)
ADP-Ribosil Ciclasa 1/fisiología , Lesión Pulmonar Aguda/prevención & control , Adenina/análogos & derivados , Agammaglobulinemia Tirosina Quinasa/antagonistas & inhibidores , Endotoxemia/prevención & control , Inflamasomas/efectos de los fármacos , Macrófagos/efectos de los fármacos , Glicoproteínas de Membrana/fisiología , Piperidinas/farmacología , Lesión Pulmonar Aguda/etiología , Lesión Pulmonar Aguda/metabolismo , Lesión Pulmonar Aguda/patología , Adenina/farmacología , Agammaglobulinemia Tirosina Quinasa/genética , Agammaglobulinemia Tirosina Quinasa/metabolismo , Animales , Endotoxemia/etiología , Endotoxemia/metabolismo , Endotoxemia/patología , Femenino , Inflamasomas/metabolismo , Macrófagos/metabolismo , Macrófagos/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , FN-kappa B/genética , FN-kappa B/metabolismo , Transducción de Señal
6.
BMC Complement Med Ther ; 20(1): 198, 2020 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-32586304

RESUMEN

BACKGROUND: The Bergenia species are perennial herbs native to central Asia, and one of the most promising medicinal plants of the family Saxifragaceae which are popularly known as 'Pashanbheda'. The aim of this study was to evaluate antioxidant and α-amylase, α-glucosidase, lipase, tyrosinase, elastase, and cholinesterases inhibition potential of Bergenia pacumbis of Nepali origin collected from the Karnali region of Nepal. METHODS: The sequential crude extracts were made in hexane, ethyl acetate, methanol, and water. Antioxidant activities were analyzed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay. The α-amylase, α-glucosidase, lipase, tyrosinase, elastase, acetylcholinesterase, and butyrylcholinesterase inhibition were analyzed by the 3,5-Dinitrosalicylic acid (DNSA), p-Nitrophenyl-α-D-glucopyranoside (p-NPG), 4-nitrophenyl butyrate (p-NPB), l-3,4-dihydroxyphenylalanine (L-DOPA), N-Succinyl-Ala-Ala-p-nitroanilide (AAAPVN), acetylthiocholine, and butyrylcholine as a respective substrate. The major metabolites were identified by high performance liquid chromatography with electron spray ionization- quadrupole time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS) profiling. RESULTS: Our results revealed the great antioxidant ability of crude extract of B. pacumbis in ethyl acetate extract against both DPPH (IC50 = 30.14 ± 0.14 µg/mL) and ABTS (IC50 = 17.38 ± 1.12 µg/mL). However, the crude methanol extract of B. pacumbis showed the comparable enzymes inhibitions with standard drugs; α-amylase (IC50 = 14.03 ± 0.04 µg/mL), α-glucosidase (IC50 = 0.29 ± 0.00 µg/mL), lipase (IC50 = 67.26 ± 0.17 µg/mL), tyrosinase (IC50 = 58.25 ± 1.63 µg/mL), elastase (IC50 = 74.00 ± 3.03 µg/mL), acetylcholinesterase (IC50 = 31.52 ± 0.58 µg/mL), and butyrylcholinesterase (IC50 = 11.69 ± 0.14 µg/mL). On the basis of HPLC-ESI-QTOF-MS profiling of metabolites, we identified major compounds such as Bergenin, Catechin, Arbutin, Gallic acid, Protocatechuic acid, Syringic acid, Hyperoside, Afzelechin, Methyl gallate, Paashaanolactone, Astilbin, Quercetin, Kaempferol-7-O-glucoside, Diosmetin, Phloretin, and Morin in methanol extract which has reported beneficial bioactivities. CONCLUSION: Our study provides a plethora of scientific evidence that the crude extracts of B. pacumbis from Nepalese origin in different extracting solvents have shown significant potential on inhibiting free radicals as well as enzymes involved in digestion, skin related problems, and neurological disorders compared with the commercially available drugs.


Asunto(s)
Antioxidantes/farmacología , Inhibidores Enzimáticos/farmacología , Extractos Vegetales/farmacología , Saxifragaceae/química , Antioxidantes/química , Colinesterasas/metabolismo , Inhibidores Enzimáticos/química , Lipasa/metabolismo , Estructura Molecular , Monofenol Monooxigenasa/metabolismo , Nepal , Elastasa Pancreática/metabolismo , Extractos Vegetales/química , alfa-Amilasas/metabolismo , alfa-Glucosidasas/metabolismo
7.
J Clin Invest ; 130(7): 3684-3698, 2020 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-32298238

RESUMEN

Unchecked inflammation is a hallmark of inflammatory tissue injury in diseases such as acute respiratory distress syndrome (ARDS). Yet the mechanisms of inflammatory lung injury remain largely unknown. Here we showed that bacterial endotoxin lipopolysaccharide (LPS) and cecal ligation and puncture-induced (CLP-induced) polymicrobial sepsis decreased the expression of transcription factor cAMP response element binding (CREB) in lung endothelial cells. We demonstrated that endothelial CREB was crucial for VE-cadherin transcription and the formation of the normal restrictive endothelial adherens junctions. The inflammatory cytokine IL-1ß reduced cAMP generation and CREB-mediated transcription of VE-cadherin. Furthermore, endothelial cell-specific deletion of CREB induced lung vascular injury whereas ectopic expression of CREB in the endothelium prevented the injury. We also observed that rolipram, which inhibits type 4 cyclic nucleotide phosphodiesterase-mediated (PDE4-mediated) hydrolysis of cAMP, prevented endotoxemia-induced lung vascular injury since it preserved CREB-mediated VE-cadherin expression. These data demonstrate the fundamental role of the endothelial cAMP-CREB axis in promoting lung vascular integrity and suppressing inflammatory injury. Therefore, strategies aimed at enhancing endothelial CREB-mediated VE-cadherin transcription are potentially useful in preventing sepsis-induced lung vascular injury in ARDS.


Asunto(s)
Antígenos CD/biosíntesis , Cadherinas/biosíntesis , Endotelio Vascular/metabolismo , Interleucina-1beta/metabolismo , Síndrome de Dificultad Respiratoria/metabolismo , Sepsis/metabolismo , Transcripción Genética , Animales , Antígenos CD/genética , Cadherinas/genética , AMP Cíclico/genética , AMP Cíclico/metabolismo , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/genética , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Endotelio Vascular/patología , Humanos , Inflamación/genética , Inflamación/metabolismo , Inflamación/patología , Interleucina-1beta/genética , Ratones , Ratones Noqueados , Síndrome de Dificultad Respiratoria/genética , Síndrome de Dificultad Respiratoria/patología , Sepsis/genética , Sepsis/patología
8.
Proc Natl Acad Sci U S A ; 116(33): 16513-16518, 2019 08 13.
Artículo en Inglés | MEDLINE | ID: mdl-31363052

RESUMEN

Efferocytosis of apoptotic neutrophils (PMNs) by alveolar macrophages (AMФs) is vital for resolution of inflammation and tissue injury. Here, we investigated the role of AMФ polarization and expression of the efferocytic ligand Gas6 in restoring homeostasis. In the murine model of lipopolysaccharide (LPS)-induced acute lung injury (ALI), we observed augmented temporal generation of cytokines IL-4 and TSG6 in bronchoalveolar fluid (BALF). Interestingly, we also observed increased expression of antiinflammatory markers consistent with a phenotype shift in AMФs. In particular, AMФs expressed the efferocytic ligand Gas6. In vitro priming of bone marrow-derived macrophages (BMMФs) with IL-4 or TSG6 also induced MФ transition and expression of Gas6. TSG6- or IL-4-primed BMMФs induced efferocytosis of apoptotic PMNs compared with control BMMФs. Adoptive transfer of TSG6- or IL-4-primed BMMФs i.t. into LPS-challenged mice more rapidly and effectively cleared PMNs in lungs compared with control BMMФs. We demonstrated that expression of Gas6 during AMФ transition was due to activation of the transcription factor signal transducer and activator of transcription-6 (STAT6) downstream of IL-4 or TSG6 signaling. Adoptive transfer of Gas6-depleted BMMФs failed to clear PMNs in lungs following LPS challenge and mice showed severely defective resolution of lung injury. Thus, activation of STAT6-mediated Gas6 expression during macrophage phenotype transition resulting in efferocytosis of PMNs plays a crucial role in the resolution of inflammatory lung injury.


Asunto(s)
Apoptosis , Inflamación/metabolismo , Inflamación/patología , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Macrófagos/metabolismo , Neutrófilos/metabolismo , Factor de Transcripción STAT6/metabolismo , Traslado Adoptivo , Animales , Moléculas de Adhesión Celular/metabolismo , Femenino , Interleucina-4/metabolismo , Lipopolisacáridos , Lesión Pulmonar/patología , Masculino , Ratones Endogámicos C57BL , Fagocitosis , Fenotipo , Alveolos Pulmonares/metabolismo , Alveolos Pulmonares/patología
11.
Circ Res ; 121(9): 1081-1091, 2017 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-28790198

RESUMEN

RATIONALE: TRPM2 (transient receptor potential melastatin-2) expressed in endothelial cells (ECs) is a cation channel mediating Ca2+ entry in response to intracellular generation of adenosine diphosphoribose-the TRPM2 ligand. OBJECTIVE: Because polymorphonuclear neutrophils (PMN) interaction with ECs generates reactive oxygen species, we addressed the possible role of TRPM2 expressed in ECs in the mechanism of transendothelial migration of PMNs. METHODS AND RESULTS: We observed defective PMN transmigration in response to lipopolysaccharide challenge in adult mice in which the EC expressed TRPM2 is conditionally deleted (Trpm2iΔEC ). PMN interaction with ECs induced the entry of Ca2+ in ECs via the EC-expressed TRPM2. Prevention of generation of adenosine diphosphoribose in ECs significantly reduced Ca2+ entry in response to PMN activation of TRPM2 in ECs. PMNs isolated from gp91phox-/- mice significantly reduced Ca2+ entry in ECs via TRPM2 as compared with wild-type PMNs and failed to induce PMN transmigration. Overexpression of the adenosine diphosphoribose insensitive TRPM2 mutant channel (C1008→A) in ECs suppressed the Ca2+ entry response. Further, the forced expression of TRPM2 mutant channel (C1008→A) or silencing of poly ADP-ribose polymerase in ECs of mice prevented PMN transmigration. CONCLUSIONS: Thus, endotoxin-induced transmigration of PMNs was secondary to TRPM2-activated Ca2+ signaling and VE-cadherin phosphorylation resulting in the disassembly of adherens junctions and opening of the paracellular pathways. These results suggest blocking TRPM2 activation in ECs is a potentially important means of therapeutically modifying PMN-mediated vascular inflammation.


Asunto(s)
Células Endoteliales/metabolismo , Activación Neutrófila/fisiología , Neutrófilos/metabolismo , Canales Catiónicos TRPM/biosíntesis , Migración Transendotelial y Transepitelial/fisiología , Lesiones del Sistema Vascular/metabolismo , Animales , Movimiento Celular/fisiología , Células Cultivadas , Células Endoteliales/patología , Expresión Génica , Humanos , Pulmón/irrigación sanguínea , Pulmón/metabolismo , Pulmón/patología , Masculino , Ratones , Ratones Noqueados , Ratones Transgénicos , Canales Catiónicos TRPM/genética , Lesiones del Sistema Vascular/genética , Lesiones del Sistema Vascular/patología
12.
Prostate ; 77(1): 10-21, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27550065

RESUMEN

BACKGROUND: Our goal was to investigate de novo purine biosynthetic gene PAICS expression and evaluate its role in prostate cancer progression. METHODS: Next-generation sequencing, qRTPCR and immunoblot analysis revealed an elevated expression of a de novo purine biosynthetic gene, Phosphoribosylaminoimidazole Carboxylase, Phosphoribosylaminoimidazole Succinocarboxamide Synthetase (PAICS) in a progressive manner in prostate cancer. Functional analyses were performed using prostate cancer cell lines- DU145, PC3, LnCaP, and VCaP. The oncogenic properties of PAICS were studied both by transient and stable knockdown strategies, in vivo chicken chorioallantoic membrane (CAM) and murine xenograft models. Effect of BET bromodomain inhibitor JQ1 on the expression level of PAICS was also studied. RESULTS: Molecular staging of prostate cancer is important factor in effective diagnosis, prognosis and therapy. In this study, we identified a de novo purine biosynthetic gene; PAICS is overexpressed in PCa and its expression correlated with disease aggressiveness. Through several in vitro and in vivo functional studies, we show that PAICS is necessary for proliferation and invasion in prostate cancer cells. We identified JQ1, a BET bromodomain inhibitor previously implicated in regulating MYC expression and demonstrated role in prostate cancer, abrogates PAICS expression in several prostate cancer cells. Furthermore, we observe loss of MYC occupancy on PAICS promoter in presence of JQ1. CONCLUSIONS: Here, we report that evaluation of PAICS in prostate cancer progression and its role in prostate cancer cell proliferation and invasion and suggest it as a valid therapeutic target. We suggest JQ1, a BET-domain inhibitor, as possible therapeutic option in targeting PAICS in prostate cancer. Prostate 77:10-21, 2017. © 2016 Wiley Periodicals, Inc.


Asunto(s)
Biomarcadores de Tumor/biosíntesis , Regulación Enzimológica de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Péptido Sintasas/biosíntesis , Neoplasias de la Próstata/enzimología , Purinas/biosíntesis , Animales , Biomarcadores de Tumor/genética , Línea Celular Tumoral , Pollos , Humanos , Masculino , Ratones , Ratones Desnudos , Invasividad Neoplásica/patología , Péptido Sintasas/genética , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/patología , Biosíntesis de Proteínas/fisiología , Ensayos Antitumor por Modelo de Xenoinjerto/métodos
13.
Proc Natl Acad Sci U S A ; 113(50): E8151-E8158, 2016 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-27911817

RESUMEN

TNFα-stimulated gene-6 (TSG6), a 30-kDa protein generated by activated macrophages, modulates inflammation; however, its mechanism of action and role in the activation of macrophages are not fully understood. Here we observed markedly augmented LPS-induced inflammatory lung injury and mortality in TSG6-/- mice compared with WT (TSG6+/+) mice. Treatment of mice with intratracheal instillation of TSG6 prevented LPS-induced lung injury and neutrophil sequestration, and increased survival in mice. We found that TSG6 inhibited the association of TLR4 with MyD88, thereby suppressing NF-κB activation. TSG6 also prevented the expression of proinflammatory proteins (iNOS, IL-6, TNFα, IL-1ß, and CXCL1) while increasing the expression of anti-inflammatory proteins (CD206, Chi3l3, IL-4, and IL-10) in macrophages. This shift was associated with suppressed activation of proinflammatory transcription factors STAT1 and STAT3. In addition, we observed that LPS itself up-regulated the expression of TSG6 in TSG6+/+ mice, suggesting an autocrine role for TSG6 in transitioning macrophages. Thus, TSG6 functions by converting macrophages from a proinflammatory to an anti-inflammatory phenotype secondary to suppression of TLR4/NF-κB signaling and STAT1 and STAT3 activation.


Asunto(s)
Moléculas de Adhesión Celular/inmunología , Lesión Pulmonar/prevención & control , Macrófagos/inmunología , Animales , Moléculas de Adhesión Celular/deficiencia , Moléculas de Adhesión Celular/genética , Reprogramación Celular/inmunología , Inflamación/prevención & control , Mediadores de Inflamación/inmunología , Lipopolisacáridos/toxicidad , Pulmón/irrigación sanguínea , Pulmón/efectos de los fármacos , Pulmón/inmunología , Activación de Macrófagos , Macrófagos/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Factor 88 de Diferenciación Mieloide/metabolismo , FN-kappa B/metabolismo , Fenotipo , Factor de Transcripción STAT1/metabolismo , Factor de Transcripción STAT3/metabolismo , Transducción de Señal , Receptor Toll-Like 4/metabolismo
14.
Am J Pathol ; 186(7): 1724-35, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27338107

RESUMEN

Multiple genetic and epigenetic events characterize tumor progression and define the identity of the tumors. Advances in high-throughput technologies, like gene expression profiling, next-generation sequencing, proteomics, and metabolomics, have enabled detailed molecular characterization of various tumors. The integration and analyses of these high-throughput data have unraveled many novel molecular aberrations and network alterations in tumors. These molecular alterations include multiple cancer-driving mutations, gene fusions, amplification, deletion, and post-translational modifications, among others. Many of these genomic events are being used in cancer diagnosis, whereas others are therapeutically targeted with small-molecule inhibitors. Multiple genes/enzymes that play a role in DNA and histone modifications are also altered in various cancers, changing the epigenomic landscape during cancer initiation and progression. Apart from protein-coding genes, studies are uncovering the critical regulatory roles played by noncoding RNAs and noncoding regions of the genome during cancer progression. Many of these genomic and epigenetic events function in tandem to drive tumor development and metastasis. Concurrent advances in genome-modulating technologies, like gene silencing and genome editing, are providing ability to understand in detail the process of cancer initiation, progression, and signaling as well as opening up avenues for therapeutic targeting. In this review, we discuss some of the recent advances in cancer genomic and epigenomic research.


Asunto(s)
Epigenómica/tendencias , Neoplasias/genética , Animales , Humanos
15.
J Cell Physiol ; 231(2): 357-69, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26089158

RESUMEN

Adiponectin predominantly secreted from adipose tissue has exhibited potent anti-proliferative properties in cancer cells via modulating cell cycle and apoptosis. FoxO3A, a Forkhead box O member of the transcription factor, plays a critical role in modulating expression of genes involved in cell death and/or survival. In this study, we investigated the role of FoxO3A signaling in anti-cancer activities of adiponectin. Herein, we have shown that treatment with globular adiponectin (gAcrp) increases p27 but decreases cyclinD1 expression in human hepatoma (HepG2) and breast (MCF-7) cancer cells. Gene ablation of FoxO3A prevented gAcrp-induced increase in p27 and decreased in cyclin D1 expression, and further ameliorated cell cycle arrest by gAcrp, indicating a critical role of FoxO3A in gAcrp-induced cell cycle arrest of cancer cells. Moreover, treatment with gAcrp also induced caspase-3/7 activation and increased Fas ligand (FasL) expression in both HepG2 and MCF-7 cells. Transfection with FoxO3A siRNA inhibited gAcrp-induced caspase-3/7 activation and FasL expression, suggesting that FoxO3A signaling also plays an important role in gAcrp-induced apoptosis of cancer cells. We also found that gene silencing of AMPK prevented gAcrp-induced nuclear translocation of FoxO3A in HepG2 and MCF-7 cells. In addition, suppression of AMPK also blocked gAcrp-induced cell cycle arrest and further attenuated gAcrp-induced caspase-3/7 activation, indicating that AMPK signaling plays a pivotal role in both gAcrp-induced cell cycle arrest and apoptosis via acting as an upstream signaling of FoxO3A. Taken together, our findings demonstrated that AMPK/FoxO3A axis plays a cardinal role in anti-proliferative effect of adiponectin in cancer cells.


Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Adiponectina/metabolismo , Factores de Transcripción Forkhead/metabolismo , Neoplasias/metabolismo , Neoplasias/patología , Quinasas de la Proteína-Quinasa Activada por el AMP , Apoptosis/fisiología , Caspasa 3/metabolismo , Caspasa 7/metabolismo , Puntos de Control del Ciclo Celular/fisiología , Proteína Ligando Fas/metabolismo , Proteína Forkhead Box O3 , Factores de Transcripción Forkhead/antagonistas & inhibidores , Factores de Transcripción Forkhead/genética , Técnicas de Inactivación de Genes , Células Hep G2 , Humanos , Células MCF-7 , Modelos Biológicos , Neoplasias/genética , Proteínas Serina-Treonina Quinasas/metabolismo , ARN Interferente Pequeño/genética , Transducción de Señal
16.
Biol Pharm Bull ; 38(7): 961-5, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26133703

RESUMEN

Adipokines, hormones predominantly produced from adipose tissue, have been shown to impart dynamic functions in the liver. Emerging evidence has shown that adipokines are also involved in modulating liver cell survival and/or death. Among the various adipokines, adiponectin and leptin directly regulate proliferation of hepatocytes, Kupffer cells, and hepatic stellate cells. Moreover, these adipokines control apoptosis and cell cycle of hepatic cancer cells in a complex manner. Adiponectin possesses both pro- and anti-proliferative properties, whereas leptin appears to play roles as a pro-survival hormone. Recent studies have revealed that regulation of cell death and proliferation is one of the critical factors regulating liver physiology by adipokines. In this review, we summarize the effects of adipokines on apoptosis and survival of liver cells and also demonstrate their implications in regulating various liver functions and decipher the underlying molecular mechanisms.


Asunto(s)
Adipoquinas/metabolismo , Hígado/metabolismo , Animales , Muerte Celular , Supervivencia Celular , Humanos
17.
Mol Cell Endocrinol ; 412: 44-55, 2015 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-26033248

RESUMEN

Adiponectin and leptin, both produced from adipose tissue, cause cell cycle arrest and progression, respectively in cancer cells. Ubiquitin specific protease-2 (USP-2), a deubiquitinating enzyme, is known to impair proteasome-induced degradation of cyclin D1, a critical cell cycle regulator. Herein, we investigated the effects of these adipokines on USP-2 expression and its potential role in the modulation of cell cycle. Treatment with globular adiponectin (gAcrp) decreased, whereas leptin increased USP-2 expression both in human hepatoma and breast cancer cells. In addition, overexpression or gene silencing of USP-2 affected cyclin D1 expression and cell cycle progression/arrest by adipokines. Adiponectin and leptin also modulated in vitro proteasomal activity, which was partially dependent on USP-2 expression. Taken together, our results reveal that modulation of USP-2 expression plays a crucial role in cell cycle regulation by adipokines. Thus, USP-2 would be a promising therapeutic target for the modulation of cancer cell growth by adipokines.


Asunto(s)
Adiponectina/fisiología , Puntos de Control del Ciclo Celular , Endopeptidasas/fisiología , Leptina/fisiología , Ciclina D1/genética , Ciclina D1/metabolismo , Expresión Génica , Células Hep G2 , Humanos , Células MCF-7 , Complejo de la Endopetidasa Proteasomal/metabolismo , Ubiquitina Tiolesterasa , Regulación hacia Arriba
18.
Oncotarget ; 6(9): 7166-81, 2015 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-25704884

RESUMEN

Leptin, a hormone mainly produced from adipose tissue, has been shown to induce proliferation of cancer cells. However, the molecular mechanisms underlying leptin-induced tumor progression have not been clearly elucidated. In the present study, we investigated the role of autophagy in leptin-induced cancer cell proliferation using human hepatoma (HepG2) and breast cancer cells (MCF-7), and tumor growth in a xenograft model. Herein, we showed that leptin treatment caused autophagy induction as assessed by increase in expression of autophagy-related genes, including beclin-1, Atg5 and LC3 II, further induction of autophagosome formation and autophagic flux. Interestingly, inhibition of autophagic process by treatment with inhibitors and LC3B gene silencing blocked leptin-induced increase in cell number and suppression of apoptosis, indicating a crucial role of autophagy in leptin-induced tumor progression. Moreover, gene silencing of p53 or FoxO3A prevented leptin-induced LC3 II protein expression, suggesting an involvement of p53/FoxO3A axis in leptin-induced autophagy activation. Leptin administration also accelerated tumor growth in BALB/c nude mice, which was found to be autophagy dependent. Taken together, our results demonstrate that leptin-induced tumor growth is mediated by autophagy induction and autophagic process would be a promising target to regulate development of cancer caused by leptin production.


Asunto(s)
Apoptosis , Autofagia/genética , Factores de Transcripción Forkhead/metabolismo , Leptina/metabolismo , Neoplasias/patología , Proteína p53 Supresora de Tumor/metabolismo , Animales , Proteínas Reguladoras de la Apoptosis/metabolismo , Proteína 5 Relacionada con la Autofagia , Beclina-1 , Progresión de la Enfermedad , Proteína Forkhead Box O3 , Silenciador del Gen , Genes p53 , Células Hep G2 , Humanos , Células MCF-7 , Masculino , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Proteínas Asociadas a Microtúbulos/metabolismo , Trasplante de Neoplasias , Proteína X Asociada a bcl-2/metabolismo
19.
Biomol Ther (Seoul) ; 22(5): 384-9, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25414767

RESUMEN

Adiponectin, an adipokine predominantly secreted from adipose tissue, exhibits diverse biological responses, including metabolism of glucose and lipid, and apoptosis in cancer cells. Recently, adiponectin has been shown to modulate autophagy as well. While emerging evidence has demonstrated that autophagy plays a role in the modulation of proliferation and apoptosis of cancer cells, the role of autophagy in apoptosis of cancer cell caused by adiponectin has not been explored. In the present study, we demonstrated that globular adiponectin (gAcrp) induces both apoptosis and autophagy in human hepatoma cell line (HepG2 cells) and breast cancer cells (MCF-7), as evidenced by increase in caspase-3 activity, Bax, microtubule-associated protein light chain 3-II (LC3 II) protein levels, and autophagosome formation. Interestingly, gene silencing of LC3B, an autophagy marker, significantly enhanced gAcrp-induced apoptosis in both HepG2 and MCF-7 cell lines, whereas induction of autophagy by rapamycin, an mTOR inhibitor, significantly prevented gAcrp-induced apoptosis in hepatoma cells HepG2. Furthermore, modulation of autophagy produced similar effects on gAcrp-induced Bax expression in HepG2 cells. These results implicate that induction of autophagy plays a regulatory role in adiponectin-induced apoptosis of cancer cells, and thus inhibition of autophagy would be a novel promising target to enhance the efficiency of cancer cell apoptosis by adiponectin.

20.
Food Chem Toxicol ; 68: 11-22, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24582693

RESUMEN

Globular adiponectin (gAcrp) protects liver cells from ethanol-induced apoptosis via induction of autophagy. However, the underlying mechanisms are unknown. The present study aims to investigate the potential role of autophagy-related protein 5 (Atg5), an essential Atg for the elongation of autophagosomes, in suppression of ethanol-induced cytotoxicity by gAcrp. Here, we demonstrated that suppression of Atg5 expression by ethanol was restored by pretreatment with gAcrp both in primary rat hepatocytes and human hepatoma cell line (HepG2). Moreover, ethanol-induced accumulation of p62 (sequestosome1), a marker of autophagic flux, was restored by gAcrp treatment, implying that gAcrp modulates autophagic flux in liver cells. Further, Atg5 silencing prevented p62 degradation by gAcrp, suggesting that Atg5 plays a critical role in induction of autophagic flux by gAcrp. Interestingly, gene silencing of Atg5 by siRNA abrogated restoration of autophagosome formation by gAcrp in ethanol-treated cells. Finally, protection of liver cells by gAcrp from ethanol-induced apoptosis was also significantly attenuated by knocking-down of Atg5 expression, suggesting an important role of Atg5 in autophagy induction and cellular apoptosis modulated by gAcrp. Taken together, our data demonstrated that Atg5 expression, at least in part, is implicated in gAcrp-induced autophagy and subsequent anti-apoptotic effects in ethanol-treated liver cells.


Asunto(s)
Adiponectina/metabolismo , Autofagia/efectos de los fármacos , Etanol/efectos adversos , Hígado/efectos de los fármacos , Proteínas Asociadas a Microtúbulos/metabolismo , Proteínas/metabolismo , Proteínas Quinasas Activadas por AMP/genética , Proteínas Quinasas Activadas por AMP/metabolismo , Animales , Proteína 5 Relacionada con la Autofagia , Caspasa 3/genética , Caspasa 3/metabolismo , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Proteína Forkhead Box O3 , Factores de Transcripción Forkhead/genética , Factores de Transcripción Forkhead/metabolismo , Regulación de la Expresión Génica , Células Hep G2 , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Humanos , Hígado/citología , Hígado/metabolismo , Masculino , Proteínas Asociadas a Microtúbulos/genética , Proteínas/genética , Ratas , Ratas Sprague-Dawley , Transducción de Señal
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...