Platelet-Activating Factor Overturns the Transcriptional Repressor Disposition of Sp1 in the Expression of<i>MMP-9</i>in Human Corneal Epithelial Cells

Taheri, Faramarz; Bazán, Haydee E. P.

doi:10.1167/iovs.06-1008

Cited by 33 publications

(18 citation statements)

References 56 publications

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“…The possible involvement of such interaction can not be excluded. Regarding the effect of PAF on Sp-1, Taheri et al [42] reported that PAF directly activates Sp-1 by phosphorylation through ERK MAPK signaling. Our unpublished data also demonstrates that PAF activates ERK, suggesting that PAF is able to activate Sp-1 in H1299 cells via ERK activation, which, in turn, may modulate the physical interaction of Sp-1 with p53 or NF-B.…”

Section: Discussionmentioning

confidence: 99%

Mechanisms of Platelet-Activating Factor-induced Enhancement of VEGF Expression

Kim

Seo

Kang

et al. 2011

Cell Physiol Biochem

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It has been previously reported that platelet-activating factor (PAF) induces the expression of vascular endothelial growth factor (VEGF) via the downregulation of p53 activity. In this study, we attempted to characterize the mechanism by which p53 activity negatively regulates PAF-induced VEGF expression. PAF increased luciferase activity as well as VEGF mRNA expression in human non-small cell lung cancer cell line H1299 transfected with VEGF luciferase reporter plasmid (VEGF-Luc). Cotransfection of the cells with wt p53, but not mutant p53, effected a blockage of PAF-induced VEGF mRNA expression. The ChIP assay revealed that p53 did not bind to the VEGF promoter. Transfection of Egr-1 or Sp-1 expression vector increased VEGF luciferase activity in VEGF-Luc-transfected cells, and this was inhibited by transfection with wt p53. The results of the Immunoprecipitation and immunoblot analysis showed that p53 binds to Egr-1 and Sp-1. Additionally, our electrophoretic mobility shift assay demonstrated that PAF induced the mobilization of Egr-1 and Sp-1 to the nucleus, and this activity was inhibited by transfection with wt p53. These data indicate that PAF inhibits protein complexes between p53 and Egr-1/Sp-1 via the downregulation of p53 levels, thus increasing the free form levels of Egr-1 and Sp-1, ultimately resulting in the transcriptional activation of VEGF.

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Section: Discussionmentioning

confidence: 99%

Mechanisms of Platelet-Activating Factor-induced Enhancement of VEGF Expression

Kim

Seo

Kang

et al. 2011

Cell Physiol Biochem

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“…This suggests that translocation of the transcription factor to the nuclei induced by PAF prevents epithelial cell apoptosis and also demonstrates a regulatory action of NF-B in PAF-induced apoptosis. Recent experiments have shown that activation of NF-B is required for gene induction of MMP-9 by PAF in corneal epithelial cells ( 117 ).…”

Section: -3 Fatty Acids and Their Derivatives Are Important In The Rementioning

confidence: 99%

Significance of lipid mediators in corneal injury and repair

Kenchegowda

Bazán

2010

Journal of Lipid Research

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ers of the cornea function in a synchronized way to ensure this transparency.Corneal tissue has three distinct layers, the epithelial, stroma, and endothelial layers, and two acellular regions, the Bowman's layer, which separates the epithelium from the stroma, and the Descemet's membrane, which is between the stroma and the endothelium ( Fig. 1A ). All three layers have a uniform and consistent arrangement throughout the tissue in order to precisely bend and transmit light, fi rst to the lens and then to the retina.The corneal epithelium is the most outer layer, consisting of fi ve to seven layers of stratifi ed nonkeratinized epithelia. The basal cells have a prominent nucleus, are mitotically active, and adhere to the basement membrane through an adhesion complex that anchors the epithelium to the Bowman's layer. Turnover of epithelial cells occurs every fi ve to seven days by displacement of existing cells, which begin their movement toward the surface to then form two to three layers of wing-shaped cells; the cells then begin terminal differentiation and desquamation. The outer-most layer of the epithelium is in intimate contact with the tear fi lm that keeps the surface moist and free of damage that can result from drying (dry eye). This is The cornea, known as the "window of the eye," has two major functions: to protect the intraocular structures and to refract light. In fact, the cornea accounts for two-thirds of the refractive power of the eye. The most important characteristic of this tissue is its transparency, and the lay-

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“…In the process of cancer invasion, cells can escape from the primary tumor, penetrate into lymphatic and blood vessels, circulate through the bloodstream, and grow into distant foci in normal tissues elsewhere in the body [13]. Cancer cells are involved in numerous interactions with the extracellular matrix and its proteins such as growth factors and cytokines.…”

Section: Discussionmentioning

confidence: 99%

Methanol Extract of Polyopes lancifolius Suppresses Tumor Necrosis Factor-α-Induced <em>Matrix</em> Metalloproteinase-9 Expression in T24 Bladder Carcinoma Cells

Jayasooriya¹,

Nam²,

Kim³

et al. 2012

Trop. J. Pharm Res

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Purpose: To investigate the effects of the methanol extract of Polyopes lancifolius (MEPL) on the expression of matrix metalloproteinase-9 (MMP-9) and invasion in T24 human bladder carcinoma cells. Methods: Reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analyses were performed to assess the expression of MMP-9 and its regulatory proteins. MMP-9 activity was evaluated using zymography while matrigel infiltration was performed to assess T24 bladder carcinoma invasion. Electrophoretic mobility assay was used to investigate the nuclear factor-κB (NF-κB) activity. Results: The expression and activity of MMP-9 were significantly increased in response to TNF-α, but MEPL suppressed TNF-α-induced MMP-9 expression and activity. MEPL also inhibited TNF-α-induced MMP-9 expression at the transcriptional level by blocking the activation of the NF-κB signaling pathway. Furthermore, the extract suppressed TNF-α-induced phosphorylation of IκBα and consequently sustained cytosolic p65 and p50 expression. Matrigel invasion assay showed that MEPL significantly reduced TNF-α-induced invasion of T24 bladder carcinoma cells. Conclusion: Collectively, these data indicate that MEPL regulates TNF-α-induced MMP-9 expression by suppressing NF-κB activity.

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Platelet-Activating Factor Overturns the Transcriptional Repressor Disposition of Sp1 in the Expression ofMMP-9in Human Corneal Epithelial Cells

Abstract: These findings demonstrate that collaboration between several regulatory elements is required for the induction of MMP-9 promoter activity by PAF and that PAF overturns the repressor effect of Sp1 through activation of the MEK/ERK signaling cascade.

Cited by 33 publications

References 56 publications

Mechanisms of Platelet-Activating Factor-induced Enhancement of VEGF Expression

Mechanisms of Platelet-Activating Factor-induced Enhancement of VEGF Expression

Significance of lipid mediators in corneal injury and repair

Methanol Extract of Polyopes lancifolius Suppresses Tumor Necrosis Factor-α-Induced <em>Matrix</em> Metalloproteinase-9 Expression in T24 Bladder Carcinoma Cells

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