Diep Nguyen - Academia.edu (original) (raw)

Papers by Diep Nguyen

Research paper thumbnail of Effects of aging on proliferation and E47 transcription factor activity induced by different stimuli in murine splenic B cells

Mechanisms of Ageing and Development, 2003

In the present paper, we have investigated the effects of aging on the expression and function of... more In the present paper, we have investigated the effects of aging on the expression and function of the E2A-encoded transcription factor E47 in splenic B lymphocytes, unactivated or activated with different stimuli (LPS, anti-CD40, anti-IgM, alone or in combination with IL-4). Results indicate that unstimulated splenic B cells show very low E47 protein levels as well as E47 DNAbinding activity and that, upon B cell activation, E47 expression and DNA-binding activity are strongly induced in young and, to a significantly lesser extent, in old mice. The level of E47 protein expression in stimulated splenic B cells was found significantly higher in young than in old mice, suggesting that DNA-binding activity correlates with protein expression. These results altogether suggest that the reduced expression of the transcriptional regulator E47 could help explain the reduced B cell functions in aging mice. #

Research paper thumbnail of Decreased E12 and/or E47 Transcription Factor Activity in the Bone Marrow As Well As in the Spleen of Aged Mice1

Research paper thumbnail of An essential role of Pak1 phosphorylation of SHARP in Notch signaling

Research paper thumbnail of Cloning and functional characterization of PELP1/MNAR promoter

Gene, 2004

Proline-, glutamic acid-and leucine-rich protein 1 (PELP1)/modulator of nongenomic activity of es... more Proline-, glutamic acid-and leucine-rich protein 1 (PELP1)/modulator of nongenomic activity of estrogen receptor (MNAR), a novel coactivator of estrogen receptors (ERs; ERa and ERh), modulates the genomic and nongenomic functions of the ERs. PELP1 expression is developmentally regulated in mammary glands and overexpressed in breast tumors. However, little is known about the regulation of PELP1. In this study, we examined whether PELP1 expression is modulated by steroid hormone 17h-estradiol (E2) -ER pathway. We found that in MCF-7 breast cancer cells, E2 upregulated PELP1 expression threefold and that this upregulation was reduced by antiestrogen. We also found that E2 modulated PELP1 levels in an actinomycin-D-sensitive manner, suggesting transcriptional regulation. Cloning and analysis of the 2-kb PELP1 promoter region revealed two estrogen-responsive element (ERE) half sites in the PELP1 promoter region. In transient transfection assays, E2 upregulated PELP1 promoter activity in breast, endometrial and osteosarcoma model cancer cell lines in an ICI 182,780-sensitive manner. We demonstrated the recruitment of ER to the PELP1 promoter in vitro using EMSA assays and in vivo using a chromatin immunoprecipitation assay. The PELP1 promoter was similarly upregulated by both ERa and ERh and differentially regulated by selective estrogen receptor modulators in a cell line-dependent manner. Our results suggest that PELP1 expression is modulated by the E2-ER pathway and that PELP1 is an ER target gene. D Abbreviations: E2, 17h-estradiol; ER, estrogen receptor; ERE, estrogen response element; PELP1, proline-, glutamic acid-and leucine-rich protein; MNAR, modulator of nongenomic activity of estrogen receptor; luc, luciferase.

Research paper thumbnail of Advanced techniques for nanocharacterization of polymeric coating surfaces

Journal of Coatings Technology and Research, 2004

Surface properties of a polymeric coating system have a strong influence on its performance and s... more Surface properties of a polymeric coating system have a strong influence on its performance and service life. However, the surface of a polymer coating may have different chemical, physical, and mechanical properties from the bulk. In order to monitor the coating property changes with environmental exposures from the early stages of degradation, nondestructive techniques with the ability to characterize surface properties with micro- to nanoscale spatial resolution are required. In this article, atomic force microscopy has been applied to study surface microstructure and morphological changes during degradation in polymer coatings. Additionally, the use of AFM with a controlled tip-sample environment to study nanochemical heterogeneity and the application of nanoindentation to characterize mechanical properties of coatings surfaces are demonstrated. The results obtained from these nanometer characterization techniques will provide a better understanding of the degradation mechanisms and a fundamental basis for predicting the service life of polymer coatings.

Research paper thumbnail of DV432 – China in Developmental perspective What challenges do civil society organizations face in contributing to China's development?

Research paper thumbnail of Effects of aging on proliferation and E47 transcription factor activity induced by different stimuli in murine splenic B cells

Mechanisms of Ageing and Development, 2003

In the present paper, we have investigated the effects of aging on the expression and function of... more In the present paper, we have investigated the effects of aging on the expression and function of the E2A-encoded transcription factor E47 in splenic B lymphocytes, unactivated or activated with different stimuli (LPS, anti-CD40, anti-IgM, alone or in combination with IL-4). Results indicate that unstimulated splenic B cells show very low E47 protein levels as well as E47 DNAbinding activity and that, upon B cell activation, E47 expression and DNA-binding activity are strongly induced in young and, to a significantly lesser extent, in old mice. The level of E47 protein expression in stimulated splenic B cells was found significantly higher in young than in old mice, suggesting that DNA-binding activity correlates with protein expression. These results altogether suggest that the reduced expression of the transcriptional regulator E47 could help explain the reduced B cell functions in aging mice. #

Research paper thumbnail of Decreased E12 and/or E47 Transcription Factor Activity in the Bone Marrow As Well As in the Spleen of Aged Mice1

Research paper thumbnail of An essential role of Pak1 phosphorylation of SHARP in Notch signaling

Research paper thumbnail of Cloning and functional characterization of PELP1/MNAR promoter

Gene, 2004

Proline-, glutamic acid-and leucine-rich protein 1 (PELP1)/modulator of nongenomic activity of es... more Proline-, glutamic acid-and leucine-rich protein 1 (PELP1)/modulator of nongenomic activity of estrogen receptor (MNAR), a novel coactivator of estrogen receptors (ERs; ERa and ERh), modulates the genomic and nongenomic functions of the ERs. PELP1 expression is developmentally regulated in mammary glands and overexpressed in breast tumors. However, little is known about the regulation of PELP1. In this study, we examined whether PELP1 expression is modulated by steroid hormone 17h-estradiol (E2) -ER pathway. We found that in MCF-7 breast cancer cells, E2 upregulated PELP1 expression threefold and that this upregulation was reduced by antiestrogen. We also found that E2 modulated PELP1 levels in an actinomycin-D-sensitive manner, suggesting transcriptional regulation. Cloning and analysis of the 2-kb PELP1 promoter region revealed two estrogen-responsive element (ERE) half sites in the PELP1 promoter region. In transient transfection assays, E2 upregulated PELP1 promoter activity in breast, endometrial and osteosarcoma model cancer cell lines in an ICI 182,780-sensitive manner. We demonstrated the recruitment of ER to the PELP1 promoter in vitro using EMSA assays and in vivo using a chromatin immunoprecipitation assay. The PELP1 promoter was similarly upregulated by both ERa and ERh and differentially regulated by selective estrogen receptor modulators in a cell line-dependent manner. Our results suggest that PELP1 expression is modulated by the E2-ER pathway and that PELP1 is an ER target gene. D Abbreviations: E2, 17h-estradiol; ER, estrogen receptor; ERE, estrogen response element; PELP1, proline-, glutamic acid-and leucine-rich protein; MNAR, modulator of nongenomic activity of estrogen receptor; luc, luciferase.

Research paper thumbnail of Advanced techniques for nanocharacterization of polymeric coating surfaces

Journal of Coatings Technology and Research, 2004

Surface properties of a polymeric coating system have a strong influence on its performance and s... more Surface properties of a polymeric coating system have a strong influence on its performance and service life. However, the surface of a polymer coating may have different chemical, physical, and mechanical properties from the bulk. In order to monitor the coating property changes with environmental exposures from the early stages of degradation, nondestructive techniques with the ability to characterize surface properties with micro- to nanoscale spatial resolution are required. In this article, atomic force microscopy has been applied to study surface microstructure and morphological changes during degradation in polymer coatings. Additionally, the use of AFM with a controlled tip-sample environment to study nanochemical heterogeneity and the application of nanoindentation to characterize mechanical properties of coatings surfaces are demonstrated. The results obtained from these nanometer characterization techniques will provide a better understanding of the degradation mechanisms and a fundamental basis for predicting the service life of polymer coatings.

Research paper thumbnail of DV432 – China in Developmental perspective What challenges do civil society organizations face in contributing to China's development?