Julia L Zhong

University of Bath, Bath, ENG, United Kingdom

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Publications (3)9.87 Total impact

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    ABSTRACT: Ultraviolet-A (UVA, 320-380 nm) radiation is an oxidative stress that strongly induces heme oxygenase 1 (HO-1) expression in cultured human primary skin fibroblasts (FEK4). In this study, we show that NF-E2-related factor 2 (Nrf2) protein accumulates and HO-1 is strongly induced following UVA irradiation of FEK4 cells. Down-regulation of Nrf2 with specific short interfering RNA (siRNA) against Nrf2 (siNrf2) largely abolished the induction of HO-1 following either UVA irradiation or hemin treatment, suggesting that Nrf2 activation mediated modulation of HO-1 by both these agents. Furthermore, a reduction of free heme levels led to a strong decrease in UVA-induced Nrf2 and HO-1 protein levels confirming a clear role for heme in the UV-mediated stress response. Knock-down of Nrf2 protein enhanced membrane damage induced by UVA irradiation, indicating that Nrf2 has a crucial protective role in these cells.
    Photochemical and Photobiological Sciences 01/2010; 9(1):18-24. · 2.92 Impact Factor
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    ABSTRACT: Adamalysins [a disintegrin and metalloproteinase (ADAM)] are a family of cell surface transmembrane proteins that have broad biological functions encompassing proteolysis, adhesion, and cell signal regulation. We previously showed that the cytoplasmic domain of ADAM-15 interacts with Src family protein tyrosine kinases and the adaptor protein growth factor receptor binding protein 2 (Grb2). In the present study, we have cloned and characterized four alternatively spliced forms of ADAM-15, which differ only in their cytoplasmic domains. We show that the four ADAM-15 variants were differentially expressed in human mammary carcinoma tissues compared with normal breast. The expression of the individual isoforms did not correlate with age, menopausal status, tumor size or grade, nodal status, Nottingham Prognostic Index, or steroid hormone receptor status. However, higher levels of two isoforms (ADAM-15A and ADAM-5B) were associated with poorer relapse-free survival in node-negative patients, whereas elevated ADAM-15C correlated with better relapse-free survival in node-positive, but not in node-negative, patients. The expression of ADAM-15A and ADAM-15B variants in MDA-MB-435 cells had differential effects on cell morphology, with adhesion, migration, and invasion enhanced by expression of ADAM-15A, whereas ADAM-15B led to reduced adhesion. Using glutathione S-transferase pull-down assays, we showed that the cytoplasmic domains of ADAM-15A, ADAM-15B, and ADAM-15C show equivalent abilities to interact with extracellular signal-regulated kinase and the adaptor molecules Grb2 and Tks5/Fish, but associate in an isoform-specific fashion with Nck and the Src and Brk tyrosine kinases. These data indicate that selective expression of ADAM-15 variants in breast cancers could play an important role in determining tumor aggressiveness by interplay with intracellular signaling pathways.
    Molecular Cancer Research 04/2008; 6(3):383-94. · 4.35 Impact Factor
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    ABSTRACT: The serine/threonine kinase Pak1 is a target of the RhoGTPases Rac and Cdc42 and an important regulator of cell morphology and migration. Recent work from several laboratories has indicated that Pak1 controls microtubule dynamics as well as the organisation of F-actin microfilaments. Pak1 is phosphorylated on T212 by the p35/Cdk5 or cyclin B1/Cdc2 kinase in postmitotic neurones and mitotic cells, respectively. To understand its function during development, we have carried out a detailed temporal and spatial analysis of Pak1 expression and phosphorylation on T212. In the embryonic forebrain, Pak1 and Pak1T212(PO4) were seen to accumulate in the corpus callosum, intermediate zone, lateral olfactory tracts, and anterior commissures. Epithelial cells of the mouse embryo lung, kidney, intestine, and skin also exhibited high levels of Pak1 and Pak1T212(PO4), suggesting a previously unsuspected role in epithelial differentiation. Pak1T212(PO4) was undetectable in all adult tissues. Together, these data indicate a specific, developmentally regulated role of the Pak1 kinase.
    Developmental Dynamics 10/2003; 228(1):121-7. · 2.59 Impact Factor

Publication Stats

52 Citations
9.87 Total Impact Points

Institutions

  • 2010
    • University of Bath
      • Department of Pharmacy and Pharmacology
      Bath, ENG, United Kingdom
  • 2008
    • University of East Anglia
      • School of Biological Sciences
      Norwich, ENG, United Kingdom
  • 2003
    • King's College London
      • MRC Centre for Developmental Neurobiology
      London, ENG, United Kingdom