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1.
Gastroenterology ; 165(2): 374-390, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37196797

RESUMEN

BACKGROUND & AIMS: Elements of field cancerization, including atrophic gastritis, metaplasia, and dysplasia, promote gastric cancer development in association with chronic inflammation. However, it remains unclear how stroma changes during carcinogenesis and how the stroma contributes to progression of gastric preneoplasia. Here we investigated heterogeneity of fibroblasts, one of the most important elements in the stroma, and their roles in neoplastic transformation of metaplasia. METHODS: We used single-cell transcriptomics to evaluate the cellular heterogeneity of mucosal cells from patients with gastric cancer. Tissue sections from the same cohort and tissue microarrays were used to identify the geographical distribution of distinct fibroblast subsets. We further evaluated the role of fibroblasts from pathologic mucosa in dysplastic progression of metaplastic cells using patient-derived metaplastic gastroids and fibroblasts. RESULTS: We identified 4 subsets of fibroblasts within stromal cells defined by the differential expression of PDGFRA, FBLN2, ACTA2, or PDGFRB. Each subset was distributed distinctively throughout stomach tissues with different proportions at each pathologic stage. The PDGFRα+ subset expanded in metaplasia and cancer compared with normal, maintaining a close proximity with the epithelial compartment. Co-culture of metaplasia- or cancer-derived fibroblasts with gastroids showing the characteristics of spasmolytic polypeptide-expressing metaplasia-induced disordered growth, loss of metaplastic markers, and increases in markers of dysplasia. Culture of metaplastic gastroids with conditioned media from metaplasia- or cancer-derived fibroblasts also promoted dysplastic transition. CONCLUSIONS: These findings indicate that fibroblast associations with metaplastic epithelial cells can facilitate direct transition of metaplastic spasmolytic polypeptide-expressing metaplasia cell lineages into dysplastic lineages.


Asunto(s)
Mucosa Gástrica , Neoplasias Gástricas , Humanos , Mucosa Gástrica/patología , Neoplasias Gástricas/patología , Hiperplasia , Metaplasia/patología , Fibroblastos/metabolismo
2.
Metabolites ; 13(3)2023 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-36984847

RESUMEN

The chronic consumption of diets rich in saturated fats leads to obesity and associated metabolic disorders including diabetes and atherosclerosis. Intake of a high-fat diet (HFD) is also recognized to dysregulate neural functions such as cognition, mood, and behavior. However, the effects of short-term high-fat diets on the brain are elusive. Here, we investigated molecular changes in the mouse brain following an acute HFD for 10 days by employing RNA sequencing and metabolomics profiling. Aberrant expressions of 92 genes were detected in the brain tissues of acute HFD-exposed mice. The differentially expressed genes were enriched for various pathways and processes such as superoxide metabolism. In our global metabolomic profiling, a total of 59 metabolites were significantly altered by the acute HFD. Metabolic pathways upregulated from HFD-exposed brain tissues relative to control samples included oxidative stress, oxidized polyunsaturated fatty acids, amino acid metabolism (e.g., branched-chain amino acid catabolism, and lysine metabolism), and the gut microbiome. Acute HFD also elevated levels of N-acetylated amino acids, urea cycle metabolites, and uracil metabolites, further suggesting complex changes in nitrogen metabolism. The observed molecular events in the present study provide a valuable resource that can help us better understand how acute HFD stress impacts brain homeostasis.

3.
Proc Natl Acad Sci U S A ; 119(27): e2121520119, 2022 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-35776543

RESUMEN

Activated Foxp3+ regulatory T (Treg) cells differentiate into effector Treg (eTreg) cells to maintain peripheral immune homeostasis and tolerance. T cell receptor (TCR)-mediated induction and regulation of store-operated Ca2+ entry (SOCE) is essential for eTreg cell differentiation and function. However, SOCE regulation in Treg cells remains unclear. Here, we show that inositol polyphosphate multikinase (IPMK), which generates inositol tetrakisphosphate and inositol pentakisphosphate, is a pivotal regulator of Treg cell differentiation downstream of TCR signaling. IPMK is highly expressed in TCR-stimulated Treg cells and promotes a TCR-induced Treg cell program. IPMK-deficient Treg cells display aberrant T cell activation and impaired differentiation into RORγt+ Treg cells and tissue-resident Treg cells. Mechanistically, IPMK controls the generation of higher-order inositol phosphates, thereby promoting Ca2+ mobilization and Treg cell effector functions. Our findings identify IPMK as a critical regulator of TCR-mediated Ca2+ influx and highlight the importance of IPMK in Treg cell-mediated immune homeostasis.


Asunto(s)
Calcio , Homeostasis , Fosfotransferasas (Aceptor de Grupo Alcohol) , Polifosfatos , Linfocitos T Reguladores , Animales , Calcio/metabolismo , Diferenciación Celular , Homeostasis/inmunología , Ratones , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Polifosfatos/metabolismo , Receptores de Antígenos de Linfocitos T/metabolismo , Linfocitos T Reguladores/enzimología , Linfocitos T Reguladores/inmunología
4.
Anim Cells Syst (Seoul) ; 26(1): 19-27, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35308129

RESUMEN

A family of inositol hexakisphosphate kinases (IP6Ks) catalyzes the production of inositol pyrophosphate IP7 (5-diphosphoinositolpentakisphosphate) which is known to modulate various biological events such as cell growth. While targeting IP6K1 in various cancer cells has been well reported to control cancer cell motility and invasiveness, the role of host IP6K1 in tumor progression remains unknown. By using a syngeneic MC38 murine mouse colon carcinoma model, here we examined how host IP6K1 in the tumor microenvironment influences tumor growth. In IP6K1 knockout (KO) mice, the growth of MC38 tumor cells was markedly accelerated and host survival was significantly shortened compared with wild-type (WT). Our flow cytometric analysis revealed that tumors grown in IP6K1 KO mice had lower immune suppressive myeloid cells and M1 polarized macrophages. Notably, infiltration of both antigen-presenting dendritic cells and CD8+ cytotoxic T lymphocytes into the tumor tissues was remarkably abrogated in IP6K1 KO condition. These studies suggest that enhanced tumor growth in IP6K1 KO mice resulted from reduced anti-tumor immunity due to disturbed immune cell actions in the tumor microenvironment. In conclusion, we demonstrate that host IP6K1 acts as a tumor suppressor, most likely by fine-tuning diverse tumor-immune cell interactions, which might have implications for improving the host response against cancer progression.

5.
Mol Cells ; 44(4): 187-194, 2021 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-33935040

RESUMEN

Inositol phosphates are water-soluble intracellular signaling molecules found in eukaryotes from yeasts to mammals, which are synthesized by a complex network of enzymes including inositol phosphate kinases. Among these, inositol polyphosphate multikinase (IPMK) is a promiscuous enzyme with broad substrate specificity, which phosphorylates multiple inositol phosphates, as well as phosphatidylinositol 4,5-bisphosphate. In addition to its catalytic actions, IPMK is known to non-catalytically control major signaling events via direct protein-protein interactions. In this review, we describe the general characteristics of IPMK, highlight its pleiotropic roles in various physiological and pathological conditions, and discuss future challenges in the field of IPMK signaling pathways.


Asunto(s)
Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Humanos , Transducción de Señal
6.
Cell Death Dis ; 10(7): 511, 2019 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-31263105

RESUMEN

In ischemic human hearts, the induction of adenosine receptor A2B (ADORA2B) is associated with cardioprotection against ischemic heart damage, but the mechanism underlying this association remains unclear. Apaf-1-interacting protein (APIP) and ADORA2B transcript levels in human hearts are substantially higher in patients with heart failure than in controls. Interestingly, the APIP and ADORA2B mRNA levels are highly correlated with each other (R = 0.912). APIP expression was significantly increased in primary neonatal cardiomyocytes under hypoxic conditions and this induction reduced myocardial cell death via the activation of the AKT-HIF1α pathway. Accordingly, infarct sizes of APIP transgenic mice after left anterior descending artery ligation were significantly reduced compared to those of wild-type mice. Strikingly, knockdown of APIP expression impaired the cytoprotective effects of ADORA2B during hypoxic damage. Immunoprecipitation and proximity ligation assays revealed that APIP interacts with ADORA2B, leading to the stabilization of both proteins by interfering with lysosomal degradation, and to the activation of the downstream PKA-CREB signaling pathways. ADORA2B levels in the hearts of APIPTg/Tg, APIPTg/+, and Apip+/- mice were proportionally downregulated. In addition, ADORA2B D296G derived from the rs200741295 polymorphism failed to bind to APIP and did not exert cardioprotective activity during hypoxia. Moreover, Adora2b D296G knock-in mice were more vulnerable than control mice to myocardial infarction and intentional increases in APIP levels overcame the defective protection of the ADORA2B SNP against ischemic injury. Collectively, APIP is crucial for cardioprotection against myocardial infarction by virtue of binding to and stabilizing ADORA2B, thereby dampening ischemic heart injury.


Asunto(s)
Proteínas Reguladoras de la Apoptosis/metabolismo , Infarto del Miocardio/metabolismo , Miocardio/metabolismo , Receptor de Adenosina A2B/metabolismo , Animales , Apoptosis/genética , Apoptosis/fisiología , Proteínas Reguladoras de la Apoptosis/genética , Línea Celular , Células Cultivadas , Femenino , Células HEK293 , Células HeLa , Humanos , Masculino , Ratones , Ratones Noqueados , Ratones Transgénicos , Infarto del Miocardio/genética , Daño por Reperfusión Miocárdica/genética , Daño por Reperfusión Miocárdica/metabolismo , Miocitos Cardíacos/metabolismo , Polimorfismo Genético/genética , Polimorfismo de Nucleótido Simple/genética , Receptor de Adenosina A2B/genética , Transducción de Señal/genética , Transducción de Señal/fisiología
7.
Korean J Women Health Nurs ; 25(4): 459-473, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37679915

RESUMEN

PURPOSE: The purpose of the study was to identify to identify the nursing needs and stress levels among spouses of women hospitalized with preterm labor, and to determine factors influencing spousal stress. METHODS: Data were collected from 95 spouses of hospitalized pregnant women due to preterm labor at a hospital in Gyeonggi province from June to December of 2016. The data were analyzed by descriptive statistics, t-test, ANOVA, Pearson's correlation coefficient, and multiple linear regression. RESULTS: The mean score of spouses' nursing needs was 3.06±0.42 and stress was 1.85±0.44 out of 4.00. The highest score of nursing needs was 3.37±0.51 in assurance and the highest score for stress was 2.26±0.72 for patient's illness and prognosis. There was a significant positive correlation between stress in spouse and nursing needs (p=.004). Stress was explained by nursing needs (ß=.28) and hospitalization days (ß=.21). CONCLUSIONS: The results of this study suggest that appropriate nursing interventions are required to address the nursing needs at the beginning of hospitalization and to reduce the stress among spouses of hospitalized pregnant women diagnosed with preterm labor.

8.
Korean J Women Health Nurs ; 25(2): 234-235, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37684860

RESUMEN

The authors found abstract and key words errors in the published article.

9.
J Korean Acad Nurs ; 48(4): 485-496, 2018 Aug.
Artículo en Coreano | MEDLINE | ID: mdl-30206199

RESUMEN

PURPOSE: This study aimed to test the mediating effect of uncertainty appraisal and coping style in the relation between uncertainty and anxiety in hospitalized pregnant women diagnosed with preterm labor. METHODS: The participants were 105 pregnant women diagnosed with preterm labor in hospitals in Korea. Data were collected from July to October 2017. The measurements included the Uncertainty in Illness Scale, Uncertainty Appraisal Scale, Coping Style Scale, and State Anxiety Inventory. Data were analyzed using descriptive statistics, an independent t-test, correlation, and multiple regression following the Baron and Kenny method and Sobel test for mediation. RESULTS: The mean score for anxiety was 2.29 out of 4.00 points and for uncertainty it was 2.46 out of 5.00 points. There were significant correlations among uncertainty, uncertainty danger appraisal, uncertainty opportunity appraisal, problem-focused coping, emotion-focused coping, and anxiety. Uncertainty danger appraisal (ß=.64, p<.001) had a complete mediating effect in the relation between uncertainty and anxiety (Z=4.54, p<.001). Uncertainty opportunity appraisal (ß=-.45, p<.001) had a complete mediating effect in the relation between uncertainty and anxiety (Z=3.28, p<.001). Emotion-focused coping (ß=-.23, p=.021) had a partial mediating effect in the relation between uncertainty and anxiety (Z=2.02, p=.044). CONCLUSION: Nursing intervention programs focusing on managing uncertainty appraisal and improving emotion-focused coping are highly recommended to decrease anxiety in hospitalized pregnant women diagnosed with preterm labor.


Asunto(s)
Adaptación Psicológica , Trabajo de Parto Prematuro/psicología , Adulto , Ansiedad , Femenino , Hospitales , Humanos , Recién Nacido , Modelos de Enfermería , Embarazo , República de Corea , Encuestas y Cuestionarios , Incertidumbre
10.
J Neurochem ; 142(5): 734-746, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28632947

RESUMEN

In neurodegenerative diseases like Alzheimer's disease (AD), tau is hyperphosphorylated and forms aggregates and neurofibrillary tangles in affected neurons. Autophagy is critical to clear the aggregates of disease-associated proteins and is often altered in patients and animal models of AD. Because mechanistic target of rapamycin (mTOR) negatively regulates autophagy and is hyperactive in the brains of patients with AD, mTOR is an attractive therapeutic target for AD. However, pharmacological strategies to increase autophagy by targeting mTOR inhibition cause various side effects. Therefore, autophagy activation mediated by non-mTOR pathways is a new option for autophagy-based AD therapy. Here, we report that pimozide activates autophagy to rescue tau pathology in an AD model. Pimozide increased autophagic flux through the activation of the AMPK-Unc-51 like autophagy activating kinase 1 (ULK1) axis, but not of mTOR, in neuronal cells, and this function was independent of dopamine D2 receptor inhibition. Pimozide reduced levels of abnormally phosphorylated tau aggregates in neuronal cells. Further, daily intraperitoneal (i.p.) treatment of pimozide led to a recovery from memory deficits of TauC3 mice expressing a caspase-cleaved form of tau. In the brains of these mice, we found increased phosphorylation of AMPK1 and ULK1, and reduced levels of the soluble oligomers and NP40-insoluble aggregates of abnormally phosphorylated tau. Together, these results suggest that pimozide rescues memory impairments in TauC3 mice and reduces tau aggregates by increasing autophagic flux through the mTOR-independent AMPK-ULK1 axis.


Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Homólogo de la Proteína 1 Relacionada con la Autofagia/metabolismo , Autofagia/fisiología , Pimozida/farmacología , Proteínas tau/metabolismo , Animales , Autofagia/efectos de los fármacos , Células Cultivadas , Antagonistas de Dopamina/farmacología , Antagonistas de Dopamina/uso terapéutico , Femenino , Células HeLa , Humanos , Masculino , Trastornos de la Memoria/metabolismo , Trastornos de la Memoria/prevención & control , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Transgénicos , Pimozida/uso terapéutico , Proteínas tau/antagonistas & inhibidores
11.
Proc Natl Acad Sci U S A ; 114(28): 7361-7366, 2017 07 11.
Artículo en Inglés | MEDLINE | ID: mdl-28652364

RESUMEN

Cell death-inducing DFF45-like effector (CIDE) domains, initially identified in apoptotic nucleases, form a family with diverse functions ranging from cell death to lipid homeostasis. Here we show that the CIDE domains of Drosophila and human apoptotic nucleases Drep2, Drep4, and DFF40 all form head-to-tail helical filaments. Opposing positively and negatively charged interfaces mediate the helical structures, and mutations on these surfaces abolish nuclease activation for apoptotic DNA fragmentation. Conserved filamentous structures are observed in CIDE family members involved in lipid homeostasis, and mutations on the charged interfaces compromise lipid droplet fusion, suggesting that CIDE domains represent a scaffold for higher-order assembly in DNA fragmentation and other biological processes such as lipid homeostasis.


Asunto(s)
Fragmentación del ADN , Desoxirribonucleasas/química , Proteínas de Unión a Poli-ADP-Ribosa/química , Proteínas/química , Animales , Apoptosis , Proteínas Reguladoras de la Apoptosis/química , Sitios de Unión , Muerte Celular , Cristalografía por Rayos X , Proteínas de Drosophila/química , Drosophila melanogaster , Homeostasis , Lípidos/química , Ratones , Microscopía Electrónica de Transmisión , Conformación Molecular , Mutación , Dominios Proteicos , Multimerización de Proteína , Proteínas/genética
12.
Korean J Women Health Nurs ; 23(1): 52-61, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37684885

RESUMEN

PURPOSE: This study was conducted to investigate the relationship of knowledge, attitudes and needs of sex education in high school students. METHODS: There were 258 participants who were high school students in S high school in G city. Data were collected from October 1 to October 31, 2011, and analyzed using SPSS/WIN 19.0. RESULTS: The mean score for sexual knowledge was 69.78, sexual attitudes was 63.66, and needs of sex education was 75.37. Sexual knowledge had positive correlation with needs of sex education (r=.17, p=.007). CONCLUSION: The findings of this study indicated a need to develop programs for high school students to increase appropriate sexual knowledge, and to encourage appropriate sexual attitudes, and to reflect needs of sex education.

13.
Mol Cancer Ther ; 15(7): 1591-601, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27196776

RESUMEN

Since its discovery in 1995, TNF-related apoptosis-inducing ligand (TRAIL) has sparked growing interest among oncologists due to its remarkable ability to induce apoptosis in malignant human cells, but not in most normal cells. However, one major drawback is its fast clearance rate in vivo Thus, the development of an alternative means of delivery may increase the effectiveness of TRAIL-based therapy. In this study, we developed a secretory TRAIL-armed natural killer (NK) cell-based therapy and assessed its cytotoxic effects on colorectal cancer cells and its tumoricidal efficacy on colorectal peritoneal carcinomatosis xenograft. We generated genetically modified NK cells by transduction with a lentiviral vector consisting of a secretion signal domain, a trimerization domain, and an extracellular domain of the TRAIL gene. These NK cells secreted a glycosylated form of TRAIL fusion protein that induced apoptotic death. Intraperitoneally, but not intravenously, injected NK cells effectively accumulated at tumor sites, infiltrated tumor tissue, induced apoptosis, and delayed tumor growth. These results shed light on the therapeutic potential of genetically engineered NK cells to treat peritoneal carcinomatosis. Mol Cancer Ther; 15(7); 1591-601. ©2016 AACR.


Asunto(s)
Neoplasias Colorrectales/inmunología , Inmunoterapia Adoptiva , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/metabolismo , Neoplasias Peritoneales/inmunología , Ligando Inductor de Apoptosis Relacionado con TNF/metabolismo , Animales , Apoptosis/genética , Apoptosis/inmunología , Línea Celular Tumoral , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Citotoxicidad Inmunológica , Modelos Animales de Enfermedad , Orden Génico , Terapia Genética/métodos , Vectores Genéticos/genética , Humanos , Masculino , Ratones , Neoplasias Peritoneales/patología , Neoplasias Peritoneales/secundario , Neoplasias Peritoneales/terapia , Ligando Inductor de Apoptosis Relacionado con TNF/genética , Ligando Inductor de Apoptosis Relacionado con TNF/farmacología , Carga Tumoral/efectos de los fármacos , Carga Tumoral/genética , Carga Tumoral/inmunología , Ensayos Antitumor por Modelo de Xenoinjerto
14.
Oncotarget ; 7(16): 21601-17, 2016 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-26942872

RESUMEN

Despite the fact that the epidermal growth factor (EGF) family member ERBB3 (HER3) is deregulated in many cancers, the list of ERBB3-interacting partners remains limited. Here, we report that the Apaf-1-interacting protein (APIP) stimulates heregulin-ß1 (HRG-ß1)/ERBB3-driven cell proliferation and tumorigenesis. APIP levels are frequently increased in human gastric cancers and gastric cancer-derived cells. Cell proliferation and tumor formation are repressed by APIP downregulation and stimulated by its overexpression. APIP's role in the ERBB3 pathway is not associated with its functions within the methionine salvage pathway. In response to HRG-ß1, APIP binds to the ERBB3 receptor, leading to an enhanced binding of ERBB3 and ERBB2 that results in sustained activations of ERK1/2 and AKT protein kinases. Furthermore, HRG-ß1/ERBB3-dependent signaling is gained in APIP transgenic mouse embryonic fibroblasts (MEFs), but not lost in Apip-/- MEFs. Our findings offer compelling evidence that APIP plays an essential role in ERBB3 signaling as a positive regulator for tumorigenesis, warranting future development of therapeutic strategies for ERBB3-driven gastric cancer.


Asunto(s)
Proteínas Reguladoras de la Apoptosis/metabolismo , Carcinogénesis/metabolismo , Receptor ErbB-2/metabolismo , Receptor ErbB-3/metabolismo , Neoplasias Gástricas/metabolismo , Animales , Proteínas Reguladoras de la Apoptosis/genética , Carcinogénesis/genética , Línea Celular Tumoral , Proliferación Celular/genética , Células Cultivadas , Femenino , Humanos , Masculino , Ratones , Ratones Noqueados , Ratones Desnudos , Ratones Transgénicos , Persona de Mediana Edad , Células 3T3 NIH , Multimerización de Proteína , Interferencia de ARN , Receptor ErbB-2/química , Receptor ErbB-2/genética , Receptor ErbB-3/química , Receptor ErbB-3/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/patología , Trasplante Heterólogo
15.
J Cell Biochem ; 117(10): 2289-301, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-26918647

RESUMEN

Cancer stem cells (CSCs) are capable of initiation and metastasis of tumors. Therefore, understanding the biology of CSCs and the interaction between CSCs and their counterpart non-stem cells is crucial for developing a novel cancer therapy. We used CSC-like and non-stem breast cancer MDA-MB-231 and MDA-MB-453 cells to investigate mammosphere formation. We investigated the role of the epithelial cadherin (E-cadherin)-extracellular signal-regulated kinase (Erk) axis in anoikis. Data from E-cadherin small hairpin RNA assay and mitogen-activated protein kinase kinase (MEK) inhibitor study show that activation of Erk, but not modulation of E-cadherin level, may play an important role in anoikis resistance. Next, the two cell subtypes were mixed and the interaction between them during mammosphere culture and xenograft tumor formation was investigated. Unlike CSC-like cells, increased secretion of interleukin-6 (IL-6) and growth-related oncogene (Gro) chemokines was detected during mammosphere culture in non-stem cells. Similar results were observed in mixed cells. Interestingly, CSC-like cells protected non-stem cells from anoikis and promoted tumor growth. Our results suggest bystander effects between CSC-like cells and non-stem cells. J. Cell. Biochem. 117: 2289-2301, 2016. © 2016 Wiley Periodicals, Inc.


Asunto(s)
Anoicis/fisiología , Neoplasias de la Mama/patología , Efecto Espectador , Células Madre Neoplásicas/patología , Células Madre/patología , Animales , Antígenos CD , Western Blotting , Neoplasias de la Mama/metabolismo , Cadherinas/metabolismo , Células Cultivadas , Femenino , Humanos , Ratones , Ratones Endogámicos NOD , Ratones SCID , Células Madre Neoplásicas/metabolismo , Transducción de Señal , Células Madre/metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto
16.
Biochim Biophys Acta ; 1863(2): 179-88, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26547035

RESUMEN

p21-Activated kinase 1 (PAK1) is a serine/threonine protein kinase implicated in cytoskeletal remodeling and cell motility. Recent studies have shown that it also promotes cell proliferation, regulates apoptosis, and increases cell transformation and invasion. In this study, we showed that NOTCH1 intracellular domain (NOTCH1-IC) negatively regulated PAK1 signaling pathway. We found a novel interaction between NOTCH1-IC and PAK1. Overexpression of NOTCH1-IC decreased PAK1-induced integrin-linked kinase 1 (ILK1) phosphorylation, whereas inhibition of NOTCH1 signaling increased PAK1-induced ILK1 phosphorylation. Notably, ILK1 phosphorylation was higher in PS1,2(-/-) cells than in PS1,2(+/+) cells. As expected, overexpression of NOTCH1-IC decreased ILK1-induced phosphorylation of glycogen synthase kinase 3 beta (GSK-3beta). Furthermore, NOTCH1-IC disrupted the interaction of PAK1 with ILK1 and altered PAK1 localization by directly interacting with it. This inhibitory effect of NOTCH1-IC on the PAK1 signaling pathway was mediated by the binding of NOTCH1-IC to PAK1 and by the alteration of PAK1 localization. Together, these results suggest that NOTCH1-IC is a new regulator of the PAK1 signaling pathway that directly interacts with PAK1 and regulates its shuttling between the nucleus and the cytoplasm.


Asunto(s)
Receptor Notch1/metabolismo , Transducción de Señal , Quinasas p21 Activadas/metabolismo , Sitios de Unión/genética , Movimiento Celular , Glucógeno Sintasa Quinasa 3/metabolismo , Glucógeno Sintasa Quinasa 3 beta , Células HEK293 , Células HeLa , Humanos , Immunoblotting , Microscopía Confocal , Modelos Biológicos , Fosforilación , Unión Proteica , Proteínas Serina-Treonina Quinasas/metabolismo , Interferencia de ARN , Receptor Notch1/genética , Quinasas p21 Activadas/genética
17.
Neurobiol Dis ; 87: 19-28, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26704708

RESUMEN

In neurodegenerative diseases like AD, tau forms neurofibrillary tangles, composed of tau protein. In the AD brain, activated caspases cleave tau at the 421th Asp, generating a caspase-cleaved form of tau, TauC3. Although TauC3 is known to assemble rapidly into filaments in vitro, a role of TauC3 in vivo remains unclear. Here, we generated a transgenic mouse expressing human TauC3 using a neuron-specific promoter. In this mouse, we found that human TauC3 was expressed in the hippocampus and cortex. Interestingly, TauC3 mice showed drastic learning and spatial memory deficits and reduced synaptic density at a young age (2-3months). Notably, tau oligomers as well as tau aggregates were found in TauC3 mice showing memory deficits. Further, i.p. or i.c.v. injection with methylene blue or Congo red, inhibitors of tau aggregation in vitro, and i.p. injection with rapamycin significantly reduced the amounts of tau oligomers in the hippocampus, rescued spine density, and attenuated memory impairment in TauC3 mice. Together, these results suggest that TauC3 facilitates early memory impairment in transgenic mice accompanied with tau oligomer formation, providing insight into the role of TauC3 in the AD pathogenesis associated with tau oligomers and a useful AD model to test drug candidates.


Asunto(s)
Caspasas/metabolismo , Trastornos de la Memoria/metabolismo , Proteínas tau/metabolismo , Animales , Reacción de Prevención/efectos de los fármacos , Reacción de Prevención/fisiología , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Encéfalo/patología , Línea Celular Tumoral , Espinas Dendríticas/efectos de los fármacos , Espinas Dendríticas/metabolismo , Espinas Dendríticas/patología , Modelos Animales de Enfermedad , Femenino , Humanos , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Aprendizaje por Laberinto/fisiología , Trastornos de la Memoria/tratamiento farmacológico , Trastornos de la Memoria/patología , Ratones Transgénicos , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Nootrópicos/farmacología , Multimerización de Proteína/efectos de los fármacos , Multimerización de Proteína/fisiología , Reconocimiento en Psicología/efectos de los fármacos , Reconocimiento en Psicología/fisiología , Sirolimus/farmacología , Memoria Espacial/efectos de los fármacos , Memoria Espacial/fisiología , Proteínas tau/genética
18.
Sci Rep ; 5: 11559, 2015 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-26109405

RESUMEN

Proteasome is a protein degradation complex that plays a major role in maintaining cellular homeostasis. Despite extensive efforts to identify protein substrates that are degraded through ubiquitination, the regulation of proteasome activity itself under diverse signals is poorly understood. In this study, we have isolated iRhom1 as a stimulator of proteasome activity from genome-wide functional screening using cDNA expression and an unstable GFP-degron. Downregulation of iRhom1 reduced enzymatic activity of proteasome complexes and overexpression of iRhom1 enhanced it. Native-gel and fractionation analyses revealed that knockdown of iRhom1 expression impaired the assembly of the proteasome complexes. The expression of iRhom1 was increased by endoplasmic reticulum (ER) stressors, such as thapsigargin and tunicamycin, leading to the enhancement of proteasome activity, especially in ER-containing microsomes. iRhom1 interacted with the 20S proteasome assembly chaperones PAC1 and PAC2, affecting their protein stability. Moreover, knockdown of iRhom1 expression impaired the dimerization of PAC1 and PAC2 under ER stress. In addition, iRhom1 deficiency in D. melanogaster accelerated the rough-eye phenotype of mutant Huntingtin, while transgenic flies expressing either human iRhom1 or Drosophila iRhom showed rescue of the rough-eye phenotype. Together, these results identify a novel regulator of proteasome activity, iRhom1, which functions via PAC1/2 under ER stress.


Asunto(s)
Estrés del Retículo Endoplásmico , Receptores ErbB/metabolismo , Chaperonas Moleculares/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Animales , Línea Celular Tumoral , Dimerización , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Fosfatasa 2 de Especificidad Dual/metabolismo , Retículo Endoplásmico/metabolismo , Estrés del Retículo Endoplásmico/efectos de los fármacos , Receptores ErbB/antagonistas & inhibidores , Receptores ErbB/genética , Células HEK293 , Humanos , Proteína Huntingtina , Proteínas de la Membrana , Chaperonas Moleculares/química , Proteínas del Tejido Nervioso/metabolismo , Estabilidad Proteica , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Tapsigargina/farmacología , Tunicamicina/farmacología , Ubiquitinación/efectos de los fármacos , Regulación hacia Arriba/efectos de los fármacos
19.
Biochem Biophys Res Commun ; 462(2): 112-8, 2015 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-25930997

RESUMEN

In Alzheimer's disease and other tauopathy, abnormal Tau proteins form intracellular aggregates and Tau filaments. However, the mechanisms that regulate Tau aggregation are not fully understood. In this paper, we show that POLDIP2 is a novel regulator of Tau aggregation. From a cell-based screening using cDNA expression library, we isolated POLDIP2 which increased Tau aggregation. Expression of POLDIP2 was increased in neuronal cells by the multiple stresses, including Aß, TNF-α and H2O2. Accordingly, ectopic expression of POLDIP2 enhanced the formation of Tau aggregates without affecting Tau phosphorylation, while down-regulation of POLDIP2 alleviated ROS-induced Tau aggregation. Interestingly, we found that POLDIP2 overexpression induced impairments of autophagy activity and partially proteasome activity and this activities were retained in DUF525 domain of POLDIP2. In a drosophila model of human tauopathy, knockdown of the drosophila POLDIP2 homolog, CG12162, attenuated rough eye phenotype induced by Tau overexpression. Further, the lifespan of neural-Tau(R406W) transgenic files were recovered by CG12162 knockdown. Together, these observations indicate that POLDIP2 plays a crucial role in Tau aggregation via the impairment of autophagy activity, providing insight into Tau aggregation in Tau pathology.


Asunto(s)
Proteínas Nucleares/metabolismo , Proteínas tau/metabolismo , Animales , Animales Modificados Genéticamente , Autofagia , Línea Celular , Modelos Animales de Enfermedad , Regulación hacia Abajo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Técnicas de Silenciamiento del Gen , Genes de Insecto , Células HEK293 , Células HeLa , Humanos , Degeneración Nerviosa/metabolismo , Degeneración Nerviosa/patología , Proteínas Nucleares/antagonistas & inhibidores , Proteínas Nucleares/genética , Complejo de la Endopetidasa Proteasomal/metabolismo , Dominios y Motivos de Interacción de Proteínas , Multimerización de Proteína , ARN Interferente Pequeño/genética , Especies Reactivas de Oxígeno/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas tau/química , Proteínas tau/genética
20.
Nat Commun ; 5: 3351, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24548998

RESUMEN

Adenylate kinase 2 (AK2), which balances adenine nucleotide pool, is a multi-functional protein. Here we show that AK2 negatively regulates tumour cell growth. AK2 forms a complex with dual-specificity phosphatase 26 (DUSP26) phosphatase and stimulates DUSP26 activity independently of its AK activity. AK2/DUSP26 phosphatase protein complex dephosphorylates fas-associated protein with death domain (FADD) and regulates cell growth. AK2 deficiency enhances cell proliferation and induces tumour formation in a xenograft assay. This anti-growth function of AK2 is associated with its DUSP26-stimulating activity. Downregulation of AK2 is frequently found in tumour cells and human cancer tissues showing high levels of phospho-FADD(Ser194). Moreover, reconstitution of AK2 in AK2-deficient tumour cells retards both cell proliferation and tumourigenesis. Consistent with this, AK2(+/-) mouse embryo fibroblasts exhibit enhanced cell proliferation with a significant alteration in phospho-FADD(Ser191). These results suggest that AK2 is an associated activator of DUSP26 and suppresses cell proliferation by FADD dephosphorylation, postulating AK2 as a negative regulator of tumour growth.


Asunto(s)
Adenilato Quinasa/metabolismo , Fosfatasas de Especificidad Dual/metabolismo , Fosfatasas de la Proteína Quinasa Activada por Mitógenos/metabolismo , Adenilato Quinasa/genética , Animales , Línea Celular , Proliferación Celular/genética , Proliferación Celular/fisiología , Fosfatasas de Especificidad Dual/genética , Electroforesis en Gel Bidimensional , Proteína de Dominio de Muerte Asociada a Fas/genética , Proteína de Dominio de Muerte Asociada a Fas/metabolismo , Células HeLa , Humanos , Técnicas In Vitro , Células MCF-7 , Masculino , Ratones , Ratones Desnudos , Fosfatasas de la Proteína Quinasa Activada por Mitógenos/genética , Fosforilación , Espectrometría de Masas en Tándem , Ensayos Antitumor por Modelo de Xenoinjerto
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