Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Sci Rep ; 13(1): 16199, 2023 09 27.
Artículo en Inglés | MEDLINE | ID: mdl-37758848

RESUMEN

With ageing populations, new elderly end-stage kidney disease (ESKD) cases rise. Unlike younger patients, elderly ESKD patients are less likely to undergo kidney transplant, and therefore the decision of receiving peritoneal dialysis (PD) and hemodialysis (HD) is more crucial. A total of 36,852 patients, aged more than 65, who were newly diagnosed with ESKD and initiated renal replacement therapy between 2013 and 2019 were identified. These patients were categorized into two groups: the PD group and the HD group according to their long-term renal replacement treatment. After propensity score matching, the PD group (n = 1628) displayed a lower incidence of major adverse cardiac and cerebrovascular events (MACCE) (10.09% vs. 13.03%, hazard ratio (HR): 0.74, 95% confidence interval (CI): 0.66-0.83), malignancy (1.23% vs. 2.14%, HR: 0.55, 95% CI: 0.40-0.76), and MACCE-associated mortality (1.35% vs. 2.25%, HR: 0.62, 95% CI: 0.46-0.84) compared to the HD group (n = 6512). However, the PD group demonstrated a higher rate of infection (34.09% vs. 24.14%, HR: 1.28, 95% CI: 1.20-1.37). The risks of all-cause mortality and infection-associated mortality were not different. This study may provide valuable clinical information to assist elderly ESKD patients to choose HD or PD as their renal replacement therapy.


Asunto(s)
Terapia de Reemplazo Renal Continuo , Fallo Renal Crónico , Diálisis Peritoneal , Anciano , Humanos , Estudios de Cohortes , Diálisis Renal/efectos adversos , Fallo Renal Crónico/terapia , Diálisis Peritoneal/efectos adversos
2.
Int J Mol Sci ; 22(22)2021 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-34830080

RESUMEN

The transcription factor Ets1 is essential for the development/differentiation of invariant Natural Killer T (iNKT) cells at multiple stages. However, its mechanisms of action and target genes in iNKT cells are still elusive. Here, we show that Ets1 is required for the optimal expression of the Vα14Jα18 T cell receptor (TCR) in post-selected thymic iNKT cells and their immediate differentiation. Ets1 is also critical for maintaining the peripheral homeostasis of iNKT cells, which is a role independent of the expression of the Vα14Jα18 TCR. Genome-wide transcriptomic analyses of post-selected iNKT cells further reveal that Ets1 controls leukocytes activation, proliferation differentiation, and leukocyte-mediated immunity. In addition, Ets1 regulates the expression of ICOS and PLZF in iNKT cells. More importantly, restoring the expression of PLZF and the Vα14Jα18 TCR partially rescues the differentiation of iNKT cells in the absence of Ets1. Taken together, our results establish a detailed molecular picture of how Ets1 regulates the stepwise differentiation of iNKT cells.


Asunto(s)
Diferenciación Celular/inmunología , Regulación de la Expresión Génica/inmunología , Células T Asesinas Naturales/inmunología , Proteína de la Leucemia Promielocítica con Dedos de Zinc/inmunología , Proteína Proto-Oncogénica c-ets-1/inmunología , Receptores de Antígenos de Linfocitos T alfa-beta/inmunología , Animales , Diferenciación Celular/genética , Ratones , Ratones Noqueados , Proteína de la Leucemia Promielocítica con Dedos de Zinc/genética , Proteína Proto-Oncogénica c-ets-1/genética , Receptores de Antígenos de Linfocitos T alfa-beta/genética
3.
Biomedicines ; 10(1)2021 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-35052695

RESUMEN

In contrast to Western counties, the incidence of urothelial carcinoma (UC) remains mar-edly elevated in Taiwan. Regulatory T cells (Tregs) play a crucial role in limiting immune responses within the tumor microenvironment. To elucidate the relationship between immune checkpoints in the tumor immune microenvironment and UC progression, we utilize the Gene Expression Omnibus (GEO) to analyze a microarray obtained from 308 patients with UC. We observed that the expression level of CD276 or TIM-3 was positively correlated with late-stage UC and poor prognosis. Patients with simultaneously high CD276 and TIM-3 expression in tumors have significantly reduced both univariate and multivariate survival, indicating that mRNA levels of these immune checkpoints could be independent prognostic biomarkers for UC overall survival and recurrence. Our cohort study showed rare CD8+ cytotoxic T-cells and Tregs infiltration during early-stage UC-known as cold tumors. Approximately 30% of late-stage tumors exhibited highly infiltrated cytotoxic T cells with high PD-1 and FOXP3 expression, which implied that cytotoxic T cells were inhibited in the advanced UC microenvironment. Collectively, our findings provide a better prognosis prediction by combined immune checkpoint biomarkers and a basis for early-stage UC standard treatment to convert cold tumors into hot tumors, followed by immune checkpoint therapy.

4.
Anticancer Res ; 40(11): 6265-6271, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33109564

RESUMEN

BACKGROUND/AIM: Colorectal cancer (CRC) is one of the most common malignant tumors in the world. This study aimed to investigate the anticancer effect of the combination treatment of Ribociclib (LEE011) and 5-Fluorouracil (5-FU) on CRC cells. MATERIALS AND METHODS: HT-29 and SW480 cells were treated with LEE011, 5-FU, or the combination of LEE011 and 5-FU. Cell viability and cycle were investigated through 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay and flow cytometry. The expression of cell cycle-related proteins was determined through western blot. RESULTS: The combined treatment of LEE011 with 5-FU synergistically reduced cell viability in HT-29 and SW480 cells. Specifically, it induced cell cycle arrest at the G1 phase, down-regulated the phosphorylation of retinoblastoma protein and the expression of p53. CONCLUSION: LEE011 exhibited potential as an effective therapeutic inhibitor for the combination treatment of CRC patients.


Asunto(s)
Aminopiridinas/farmacología , Neoplasias Colorrectales/patología , Fluorouracilo/farmacología , Purinas/farmacología , Puntos de Control del Ciclo Celular/efectos de los fármacos , Proteínas de Ciclo Celular/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Sinergismo Farmacológico , Humanos
5.
Tissue Eng Regen Med ; 17(5): 671-682, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32880852

RESUMEN

BACKGROUND: This study investigated whether xenotransplantation of human Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) reduces thioacetamide (TAA)-induced mouse liver fibrosis and the underlying molecular mechanism. METHODS: Recipient NOD/SCID mice were injected intraperitoneally with TAA twice weekly for 6 weeks before initial administration of WJ-MSCs. Expression of regenerative and pro-fibrogenic markers in mouse fibrotic livers were monitored post cytotherapy. A hepatic stallate cell line HSC-T6 and isolated WJ-MSCs were used for in vitro adhesion, migration and mechanistic studies. RESULTS: WJ-MSCs were isolated from human umbilical cords by an explant method and characterized by flow cytometry. A single infusion of WJ-MSCs to TAA-treated mice significantly reduced collagen deposition and ameliorated liver fibrosis after 2-week therapy. In addition to enhanced expression of hepatic regenerative factor, hepatocyte growth factor, and PCNA proliferative marker, WJ-MSC therapy significantly blunted pro-fibrogenic signals, including Smad2, RhoA, ERK. Intriguingly, reduction of plasma fibronectin (pFN) in fibrotic livers was noted in MSC-treated mice. In vitro studies further demonstrated that suspending MSCs triggered pFN degradation, soluble pFN conversely retarded adhesion of suspending MSCs onto type I collagen-coated surface, whereas pFN coating enhanced WJ-MSC migration across mimicked wound bed. Moreover, pretreatment with soluble pFN and conditioned medium from MSCs with pFN strikingly attenuated the response of HSC-T6 cells to TGF-ß1-stimulation in Smad2 phosphorylation and RhoA upregulation. CONCLUSION: These findings suggest that cytotherapy using WJ-MSCs may modulate hepatic pFN deposition for a better regenerative niche in the fibrotic livers and may constitute a useful anti-fibrogenic intervention in chronic liver diseases.


Asunto(s)
Células Madre Mesenquimatosas , Animales , Humanos , Hígado , Ratones , Ratones Endogámicos NOD , Ratones SCID , Tioacetamida/toxicidad
7.
PLoS One ; 14(11): e0225537, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31756179

RESUMEN

There is high risk of metastasis and recurrence in head and neck squamous cell carcinoma (HNSCC) patients, especially for patient who received definitive surgery and adjuvant radiotherapy. Aberrant activation of PI3K/AKT/mTOR signaling occurs in approximately 80% of HNSCC, which has been indicated to serve as prognostic biomarkers for patients suffer from recurrence or metastasis. Therefore, in this study, we focus on the relationship between the expression level of signaling factors in PI3K/AKT/mTOR pathway and recurrence tumor from HNSCC patients. A tissue microarray (TMA) was constructed from 54 cases of HNSCC patients who received definitive surgery and adjuvant radiotherapy, are followed more than 5 years, and with no previous malignancy and synchronous tumor. Slides were scored and dichotomized by two pathologists and scores. Based on the TMA block with IHC staining, the results showed that PI3K/AKT/mTOR signaling was highly activated both in recurrence and non-recurrence patients. Particularly, in the recurrence population, the results showed the low expression phospho-eukaryotic initiation factor 4E (p-eIF4E) or high expression eIF4E, phospho-eIF4E binding protein 1 (p-4EBP1), phospho-ribosomal protein S6 kinase beta-1 (p-S6K1) and phospho-40S ribosomal protein S6 (p-S6R) exhibited worse overall survival. The expression level of eIF4E and p-4EBP1 were significantly associated with tumor recurrence and recurrence-free survival. Furthermore, high expression level of eIF4E and p-4EBP1 had worse recurrence-free survival. In conclusion, the expression of eIF4E and p-4EBP1 should be considered as predictive biomarkers for the HNSCC patients. This may contribute to potential predictive biomarkers for HNSCC patient who receive adjuvant radiotherapy.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Biomarcadores de Tumor/metabolismo , Carcinoma de Células Escamosas/radioterapia , Proteínas de Ciclo Celular/metabolismo , Factor 4E Eucariótico de Iniciación/metabolismo , Neoplasias de Cabeza y Cuello/radioterapia , Adulto , Carcinoma de Células Escamosas/mortalidad , Carcinoma de Células Escamosas/cirugía , Femenino , Regulación Neoplásica de la Expresión Génica , Neoplasias de Cabeza y Cuello/mortalidad , Neoplasias de Cabeza y Cuello/cirugía , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia , Fosfatidilinositol 3-Quinasas/metabolismo , Pronóstico , Proteínas Proto-Oncogénicas c-akt/metabolismo , Radioterapia Adyuvante , Transducción de Señal , Tasa de Supervivencia , Serina-Treonina Quinasas TOR
8.
Anticancer Res ; 39(9): 4829-4835, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31519585

RESUMEN

BACKGROUND/AIM: Chronic lymphocytic leukemia (CLL) still remains an incurable disease as the cells evade apoptosis, which is an obstacle for current therapeutic approaches. Therefore, our aim was to identify an ideal target of leukemic cell growth for developing inhibitors. MATERIALS AND METHODS: Mouse lymphocytic leukemia cell line L1210, human Toledo cells and a DBA/2 mouse graft model were used to analyze the activity of dual mTORC1/2 inhibitor AZD2014s. Western blotting and flow cytometry were performed to determine the mechanism. RESULTS: AZD2014 inhibited L1210 and human Toledo cell proliferation. Treatment with AZD2014 reduced the phosphorylation levels of S6K1 and 4EBP1 and the protein levels of Rictor, a component of the mTORC2 pathway. AZD2014 induced cell cycle arrest at the G0-G1 phase by reducing the expression of cyclin D1 and CDK4. Oral administration of AZD2014 significantly inhibited the growth of L1210 cell grafts in DBA/2 mice. CONCLUSION: The mTORC1/2 inhibitor may be a better therapeutic agent compared to PI3K/mTORC1 inhibitors for treating patients with CLL.


Asunto(s)
Antineoplásicos/farmacología , Diana Mecanicista del Complejo 1 de la Rapamicina/antagonistas & inhibidores , Diana Mecanicista del Complejo 2 de la Rapamicina/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/farmacología , Animales , Apoptosis/efectos de los fármacos , Benzamidas , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Humanos , Leucemia Linfoide/tratamiento farmacológico , Leucemia Linfoide/metabolismo , Leucemia Linfoide/patología , Masculino , Ratones , Morfolinas/farmacología , Pirimidinas
9.
BMB Rep ; 52(9): 548-553, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31072446

RESUMEN

Ets-1 is a prototype of the ETS protein family. Members of the ETS protein family contain a unique ETS domain. Ets-1 is associated with cancer progression and metastasis in many types of cancer. Many studies have shown a link between elevated expression of Ets-1 in cancer biopsies and poor survival. CCR7 is a chemokine that binds to specific ligand CCL21/CCL19. CCR7 expression is associated with tumor metastasis and infiltration into lymph nodes. The objective of this study was to test whether Ets-1 could regulate CCR7 expression and enhance tumor metastasis. Our data showed that CCR7 expression was downregulated in Ets-1-deficient T cells upon T-cell stimulation. Overexpression of Ets-1 increased CCR7 expression in breast cancer cell lines. In contrast, knockdown of Ets-1 reduced CCR7 expression. Ets-1 could directly bind to CCR7 promoter and mediate CCR7 expression in luciferase reporter assays and chromatin immunoprecipitation assays. Transactivation activity of Ets-1 was independent of the Pointed domain of Ets-1. Ets-1 could also enhance NF-κB and CBP transactivation of CCR7 promoter. Our results also showed that Ets-1 could modulate cancer cell transmigration by altering CCR7 expression in transwell assay and wound healing assay. Taken together, our data suggest that Ets-1 can enhance CCR7 expression and contribute to tumor cell migration. [BMB Reports 2019; 52(9): 548-553].


Asunto(s)
Regulación Neoplásica de la Expresión Génica/genética , Proteína Proto-Oncogénica c-ets-1/metabolismo , Receptores CCR7/genética , Receptores CCR7/metabolismo , Línea Celular Tumoral , Movimiento Celular/genética , Quimiocina CCL19/genética , Quimiocina CCL19/metabolismo , Quimiocina CCL21/genética , Quimiocina CCL21/metabolismo , Femenino , Humanos , FN-kappa B/metabolismo , Proteína Proto-Oncogénica c-ets-1/genética , Transducción de Señal/genética , Transducción de Señal/fisiología
10.
Anticancer Res ; 39(2): 713-720, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30711949

RESUMEN

BACKGROUND: Radiotherapy (RT) combined with a radiosensitizer represents an important treatment for head and neck squamous cell carcinoma (HNSCC). Only few chemotherapy agents are currently approved as radiosensitizers for targeted therapy. In this study, the potent cyclin-dependent kinase 4/6 (CDK4/6) inhibitor LEE011 was tested for potential to act as a radiosensitizer during RT. MATERIALS AND METHODS: RT enhancement by LEE011 was assessed by in vitro clonogenic assay, flow cytometry, and western blot in a variety of HNSCC cell lines. The HNSCC cell line OML1 and its radiation-resistant clone OML1-R were used. RESULTS: LEE011 induced cell-cycle arrest in SCC4/SCC25 cells during the G1/M phase through inhibition of retinoblastoma protein phosphorylation. LEE011 enhanced the effects of radiation in OML1 cells and overcame radiation resistance in OML1-R cells. CONCLUSION: LEE011 is a potential radiosensitizer that can enhance the cytotoxic effects of RT. Clinical trials including LEE011 during RT for HNSCC should be considered.


Asunto(s)
Aminopiridinas/farmacología , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Neoplasias de Cabeza y Cuello/radioterapia , Purinas/farmacología , Fármacos Sensibilizantes a Radiaciones/farmacología , Carcinoma de Células Escamosas de Cabeza y Cuello/tratamiento farmacológico , Carcinoma de Células Escamosas de Cabeza y Cuello/radioterapia , Apoptosis/efectos de los fármacos , Ciclo Celular , Línea Celular Tumoral , Proliferación Celular , Quinasa 4 Dependiente de la Ciclina/antagonistas & inhibidores , Quinasa 6 Dependiente de la Ciclina/antagonistas & inhibidores , Humanos , Neoplasias de la Boca/tratamiento farmacológico , Neoplasias de la Boca/radioterapia , Fosforilación , Proteínas de Unión a Retinoblastoma/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo
11.
Life Sci ; 184: 37-46, 2017 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-28689803

RESUMEN

AIMS: Endotoxemia and its pro-fibrogenic signaling play a significant role in the development of hepatic fibrosis. This study investigated whether lipopolysaccharide (LPS) directly activate cultured HSC-T6 hepatic stellate cells (HSCs) through triggering Smad-dependent pro-fibrogenic signaling pathway. MAIN METHODS: Direct cell counting and assays for cell proliferation and migration were used to measure the effects of LPS on HSC behaviors. Quantitative PCR, Western blot, and gelatin zymography were used to quantify the molecular effects of LPS on expression of HSC activation markers and signaling activity. KEY FINDINGS: Long-term exposure to LPS exhibited moderately stimulatory effect on HSC cell growth. A wound-healing cell migration assay showed that LPS suppressed HSC-T6 cell migration. qPCR and Western blotting detection indicated that LPS treatment induced upregulation of type I and IV collagens, α-smooth muscle actin (α-SMA), and matrix metalloproteinase-9 (MMP-9). Gelatin zymography confirmed that LPS elevated MMP-9, but not MMP-2 gelatinolytic activity. Moreover, LPS immediately stimulated Akt, EKR1/2, JNK, p38 MAPK, and Smad2 hyperphosphorylation, supporting that LPS directly triggers pro-fibrogenic Smad signaling cascade without TGF-ß1 stimulation. Kinase blockade experiments demonstrated the involvement of PI3K/Akt, JNK, p38 MAPK, but not ERK1/2 signaling activation in the LPS-elicited Smad2 phosphorylation as well as the overexpression of type I collagen and α-SMA in HSC-T6 cells. SIGNIFICANCE: These findings demonstrate that LPS exerts pro-fibrogenic effect through activation and transformation of HSCs. The tissue-remodeling effect of LPS may be attributable to its ability to activate non-canonical Smad pathway through PI3K/Akt and MAPK signaling cascades.


Asunto(s)
Proliferación Celular/efectos de los fármacos , Células Estrelladas Hepáticas/efectos de los fármacos , Lipopolisacáridos/farmacología , Transducción de Señal/efectos de los fármacos , Proteína Smad2/metabolismo , Animales , Western Blotting , Línea Celular , Movimiento Celular/efectos de los fármacos , Colágeno Tipo I/metabolismo , Endotoxemia/fisiopatología , Células Estrelladas Hepáticas/metabolismo , Lipopolisacáridos/administración & dosificación , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Fosfatidilinositol 3-Quinasa/metabolismo , Fosforilación/efectos de los fármacos , Reacción en Cadena de la Polimerasa , Ratas , Ratas Sprague-Dawley , Factores de Tiempo
12.
Chin Med ; 12: 9, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28400856

RESUMEN

BACKGROUND: Glossogyne tenuifolia (GT) (Hsiang-ju) is a Chinese herbal medicine previously exhibited an anti-inflammatory activity. This study aimed to investigate the effect of GT ethanol extract (GTE) on T cell-mediated adaptive immunity. METHODS: Human peripheral blood mononuclear cells (PBMCs) and Jurkat T cells were activated by phytohemagglutinin in the presence of various doses (3.13-50 µg/mL) of GTE. The effect of GTE on T cell activation was examined by a proliferation assay of activated PBMCs and the level of the activation marker CD69 on the surface of activated Jurkat T cells. Apoptosis was determined by propidium iodide staining in hypotonic solution. Signaling pathway molecules were assessed by western blotting. RESULTS: Glossogyne tenuifolia ethanol extract was demonstrated to inhibit T cell activation, not only in the proliferation of human PBMCs at the concentrations of 12.5, 25 and 50 µg/mL (P = 0.0118, 0.0030 and 0.0021) but also in the CD69 expression in Jurkat cells, which was not due to the cytotoxicity of GTE. The presence of GTE did not change the activity of nuclear factor kappa-light-chain-enhancer of activated B cells or extracellular signal-regulated kinase upon T cell activation. In addition, GTE significantly reduced activation of c-Jun N-terminal kinase (JNK) (P = 0.0167) and p38 (P = 0.0278). Furthermore, decreased JNK activation mediated the preventive effect of GTE on T cell activation-induced cell death (AICD). CONCLUSION: Glossogyne tenuifolia ethanol extract inhibited T cell activation of Jurkat cells and freshly prepared human PBMCs due to suppression of JNK activity. Furthermore, GTE inhibited AICD by blocking prolonged JNK phosphorylation in activated T cells. Taken together, the anti-inflammatory effects exerted by GTE were mediated via suppression of JNK phosphorylation in T cell activation.

13.
PLoS One ; 10(5): e0127617, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25993510

RESUMEN

C-Maf plays an important role in regulating cytokine production in TH cells. Its transactivation of IL-4 is optimized by phosphorylation at Tyr21, Tyr92, and Tyr131. However, the molecular mechanism regulating its tyrosine phosphorylation remains unknown. In this study, we demonstrate that Tec kinase family member Tec, but not Rlk or Itk, is a tyrosine kinase of c-Maf and that Tec enhances c-Maf-dependent IL-4 promoter activity. This effect of Tec is counteracted by Ptpn22, which physically interacts with and facilitates tyrosine dephosphorylation of c-Maf thereby attenuating its transcriptional activity. We further show that phosphorylation of Tyr21/92/131 of c-Maf is also critical for its recruitment to the IL-21 promoter and optimal production of this cytokine by TH17 cells. Thus, manipulating tyrosine phosphorylation of c-Maf through its kinases and phosphatases can have significant impact on TH cell-mediated immune responses.


Asunto(s)
Fosfotirosina/metabolismo , Proteína Tirosina Fosfatasa no Receptora Tipo 22/metabolismo , Proteínas Tirosina Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-maf/metabolismo , Animales , Núcleo Celular/metabolismo , Células HEK293 , Humanos , Interleucina-4/genética , Interleucinas/biosíntesis , Ratones Endogámicos C57BL , Ratones Noqueados , Fosforilación , Regiones Promotoras Genéticas/genética , Unión Proteica , Células Th17/metabolismo , Activación Transcripcional/genética , Técnicas del Sistema de Dos Híbridos
14.
PLoS One ; 9(5): e96535, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24831988

RESUMEN

The integral membrane protein 2a (Itm2a) is one of the BRICHOS domain-containing proteins and is structurally related to Itm2b and Itm2c. It is expressed preferentially in the T lineage among hematopoietic cells and is induced by MHC-mediated positive selection. However, its transcriptional regulation and function are poorly understood. Here we showed Itm2a to be a target gene of GATA-3, a T cell-specific transcription factor. Deficiency of Itm2a had little impact on the development and function of polyclonal T cells but resulted in a partial defect in the development of thymocytes bearing a MHC class I-restricted TCR, OT-I. In addition, Itm2a-deficient mice displayed an attenuated T helper cell-dependent immune response in vivo. We further demonstrated that Itm2b but not Itm2c was also expressed in T cells, and was induced upon activation, albeit following a kinetic different from that of Itm2a. Thus, functional redundancy between Itm2a and Itm2b may explain the minimal phenotype of Itm2a deficiency.


Asunto(s)
Factor de Transcripción GATA3/metabolismo , Proteínas de la Membrana/fisiología , Linfocitos T/citología , Timocitos/citología , Animales , Diferenciación Celular/genética , Femenino , Citometría de Flujo , Regulación de la Expresión Génica , Inmunidad Celular , Masculino , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Fenotipo , Estructura Terciaria de Proteína
15.
Proc Natl Acad Sci U S A ; 110(39): 15776-81, 2013 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-24019486

RESUMEN

E26 transformation-specific sequence 1 (Ets-1), the prototype of the ETS family of transcription factors, is critical for the expression of IL-2 by murine Th cells; however, its mechanism of action is still unclear. Here we show that Ets-1 is also essential for optimal production of IL-2 by primary human Th cells. Although Ets-1 negatively regulates the expression of Blimp1, a known suppressor of IL-2 expression, ablation of B lymphocyte-induced maturation protein 1 (Blimp1) does not rescue the expression of IL-2 by Ets-1-deficient Th cells. Instead, Ets-1 physically and functionally interacts with the nuclear factor of activated T-cells (NFAT) and is required for the recruitment of NFAT to the IL-2 promoter. In addition, Ets-1 is located in both the nucleus and cytoplasm of resting Th cells. Nuclear Ets-1 quickly exits the nucleus in response to calcium-dependent signals and competes with NFAT proteins for binding to protein components of noncoding RNA repressor of NFAT complex (NRON), which serves as a cytoplasmic trap for phosphorylated NFAT proteins. This nuclear exit of Ets-1 precedes rapid nuclear entry of NFAT and Ets-1 deficiency results in impaired nuclear entry, but not dephosphorylation, of NFAT proteins. Thus, Ets-1 promotes the expression of IL-2 by modulating the activity of NFAT.


Asunto(s)
Núcleo Celular/metabolismo , Interleucina-2/genética , Factores de Transcripción NFATC/metabolismo , Regiones Promotoras Genéticas , Proteína Proto-Oncogénica c-ets-1/metabolismo , Animales , Secuencia de Bases , Calcio/metabolismo , Técnicas de Inactivación de Genes , Humanos , Interleucina-2/biosíntesis , Ratones , Datos de Secuencia Molecular , Complejos Multiproteicos/metabolismo , Factor 1 de Unión al Dominio 1 de Regulación Positiva , Unión Proteica/genética , Transporte de Proteínas , Proteína Proto-Oncogénica c-ets-1/deficiencia , Transducción de Señal , Células TH1/metabolismo , Factores de Transcripción/deficiencia , Factores de Transcripción/metabolismo
16.
J Immunol ; 190(1): 428-37, 2013 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-23225883

RESUMEN

GATA-3, a C2C2-type zinc finger transcription factor, regulates many steps of T cell development and differentiation. It is also required for optimal production of type 2 cytokines by CD8(+) T cells. However, its role in the development and function of this subset of T cells is still poorly characterized. In this paper, we report that GATA-3 is required for MHC-mediated positive selection and final maturation of CD8 single-positive thymocytes. Deficiency of GATA-3 mediated by a CD4cre transgene led to age-dependent lymphadenopathy partly because of abnormal expansion of CD8(+) T cells driven by a cell-extrinsic mechanism. Paradoxically, GATA-3-deficient CD8(+) T cells were hyporesponsive to Ag stimulation due to a defect in the maintenance/progression, but not initiation, of activation signals. More importantly, GATA-3-deficient CD8(+) T cells were less efficient in killing Ag-bearing tumor cells in vivo. Taken together, our data further expand the role of GATA-3 in T cells.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Factor de Transcripción GATA3/fisiología , Homeostasis/inmunología , Activación de Linfocitos/inmunología , Animales , Línea Celular Tumoral , Femenino , Factor de Transcripción GATA3/deficiencia , Factor de Transcripción GATA3/genética , Homeostasis/genética , Activación de Linfocitos/genética , Masculino , Melanoma Experimental , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos
17.
PLoS One ; 7(3): e33067, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22427951

RESUMEN

PTPN22 is a tyrosine phosphatase and functions as a damper of TCR signals. A C-to-T single nucleotide polymorphism (SNP) located at position 1858 of human PTPN22 cDNA and converting an arginine (R620) to tryptophan (W620) confers the highest risk of rheumatoid arthritis among non-HLA genetic variations that are known to be associated with this disease. The effect of the R-to-W conversion on the phosphatase activity of PTPN22 protein and the impact of the minor T allele of the C1858T SNP on the activation of T cells has remained controversial. In addition, how the overall activity of PTPN22 is regulated and how the R-to-W conversion contributes to rheumatoid arthritis is still poorly understood. Here we report the identification of an alternative splice form of human PTPN22, namely PTPN22.6. It lacks the nearly entire phosphatase domain and can function as a dominant negative isoform of the full length PTPN22. Although conversion of R620 to W620 in the context of PTPN22.1 attenuated T cell activation, expression of the tryptophan variant of PTPN22.6 reciprocally led to hyperactivation of human T cells. More importantly, the level of PTPN22.6 in peripheral blood correlates with disease activity of rheumatoid arthritis. Our data depict a model that can reconcile the conflicting observations on the functional impact of the C1858T SNP and also suggest that PTPN22.6 is a novel biomarker of rheumatoid arthritis.


Asunto(s)
Empalme Alternativo/genética , Artritis Reumatoide/sangre , Biomarcadores/sangre , Modelos Biológicos , Proteína Tirosina Fosfatasa no Receptora Tipo 22/sangre , Proteína Tirosina Fosfatasa no Receptora Tipo 22/genética , Linfocitos T/inmunología , Artritis Reumatoide/genética , Western Blotting , Línea Celular Tumoral , Cartilla de ADN/genética , ADN Complementario/genética , Ensayo de Inmunoadsorción Enzimática , Humanos , Inmunoprecipitación , Leucocitos Mononucleares , Modelos Lineales , Luciferasas , Activación de Linfocitos/genética , Mutación Missense/genética , Polimorfismo de Nucleótido Simple/genética , Isoformas de Proteínas/sangre , Isoformas de Proteínas/genética , Reacción en Cadena en Tiempo Real de la Polimerasa
18.
J Immunol ; 186(2): 969-76, 2011 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-21148801

RESUMEN

The expression of CD127, the IL-7-binding subunit of the IL-7 R, is tightly regulated during the development and activation of T cells and is reduced during chronic viral infection. However, the molecular mechanism regulating the dynamic expression of CD127 is still poorly understood. In this study, we report that the transcription factor Ets-1 is required for maintaining the expression of CD127 in murine peripheral T cells. Ets-1 binds to and activates the CD127 promoter, and its absence leads to reduced CD127 expression, attenuated IL-7 signaling, and impaired IL-7-dependent homeostatic proliferation of T cells. The expression of CD127 and Ets-1 is strongly correlated in human T cells. Both CD127 and Ets-1 expression are decreased in CD8(+) T cells during HIV infection. In addition, HIV-associated loss of CD127 is only observed in Ets-1(low) effector memory and central memory but not in Ets-1(high) naive CD8(+) T cells. Taken together, our data identify Ets-1 as a critical regulator of CD127 expression in T cells.


Asunto(s)
Interleucina-7/biosíntesis , Proteína Proto-Oncogénica c-ets-1/fisiología , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Animales , Células Cultivadas , Femenino , VIH-1/inmunología , Humanos , Interleucina-7/genética , Subunidad alfa del Receptor de Interleucina-7/biosíntesis , Subunidad alfa del Receptor de Interleucina-7/genética , Subunidad alfa del Receptor de Interleucina-7/metabolismo , Masculino , Ratones , Ratones Noqueados , Regiones Promotoras Genéticas/inmunología , Unión Proteica/inmunología , Proteína Proto-Oncogénica c-ets-1/deficiencia , Proteína Proto-Oncogénica c-ets-1/genética , Proteína Proto-Oncogénica c-ets-1/metabolismo , Subgrupos de Linfocitos T/virología
19.
Nat Rev Immunol ; 9(2): 125-35, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19151747

RESUMEN

Many advances in our understanding of the molecules that regulate the development, differentiation and function of T cells have been made over the past few years. One important regulator of T-cell differentiation is the transcription factor GATA-binding protein 3 (GATA3). Although the main function of GATA3 is to act as a master transcription factor for the differentiation of T helper 2 (T(H)2) cells, new research has helped to uncover crucial functions of GATA3 in T cells that go beyond T(H)2-cell differentiation and that are important at earlier stages of haematopoietic and lymphoid-cell development. This Review focuses on the functions of GATA3 from early thymocyte development to effector T-cell differentiation. In addition, we discuss the interactions between GATA3 and other transcription factors and signalling pathways, and highlight the functional significance of the GATA3 protein structure.


Asunto(s)
Linaje de la Célula/inmunología , Factor de Transcripción GATA3/metabolismo , Células Th2/inmunología , Secuencia de Aminoácidos , Animales , Factor de Transcripción GATA3/química , Humanos , Linfopoyesis , Datos de Secuencia Molecular , Transducción de Señal , Timo/inmunología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...