IL-1β, an immediate early protein secreted by activated microglia, induces iNOS/NO in C6 astrocytoma cells through p38 MAPK and NF-κB pathways

2006 ◽  
Vol 84 (5) ◽  
pp. 1037-1046 ◽  
Author(s):  
Yun-Jung Kim ◽  
So-Young Hwang ◽  
Eok-Soo Oh ◽  
Seikwan Oh ◽  
Inn-Oc Han
Keyword(s):  
P38 Mapk ◽  
Immediate Early ◽  
Activated Microglia ◽  
Astrocytoma Cells ◽  
Early Protein ◽  
C6 Astrocytoma

Release of collagen type IV degrading activity from C6 astrocytoma cells and cell density

1996 ◽  
Vol 84 (6) ◽  
pp. 1013-1019 ◽  
Author(s):  
Masashi Tamaki ◽  
Warren McDonald ◽  
Rolando F. Del Maestro
Keyword(s):  
Cell Density ◽  
Collagen Type ◽  
Cell Communication ◽  
Collagen Type Iv ◽  
Major Protein ◽  
Content Type ◽  
Type Iv ◽  
Astrocytoma Cells ◽  
C6 Astrocytoma

✓ Type IV collagen is a major protein component of the vascular basement membrane and its degradation is crucial to the initiation of tumor-associated angiogenesis. The authors have investigated the influence of cell density on the release of collagen type IV degrading activity by C6 astrocytoma cells in monolayer culture. The release of collagen type IV degrading activity was assessed biochemically, immunocytochemically, and by Western blot analysis. The results demonstrate that increasing plating density and increasing cell density are associated with decreased collagen type IV degrading activity released per tumor cell. These findings indicate the existence of regulatory mechanisms dependent on cell—cell communication, which modulate release of collagen type IV degrading activity. The extrapolation of these results to the in vivo tumor microenvironment would suggest that individual and/or small groups of invading tumor cells, distant from the main tumor mass, would release substantial collagen type IV degrading activity, which may be crucial to their continued invasion and to angiogenesis.

scholarly journals Herpes Simplex Virus ICP27 Is Required for Virus-Induced Stabilization of the ARE-Containing IEX-1 mRNA Encoded by the Human IER3 Gene

2006 ◽  
Vol 80 (19) ◽  
pp. 9720-9729 ◽  
Author(s):  
Jennifer A. Corcoran ◽  
Wei-Li Hsu ◽  
James R. Smiley
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Mapk Pathway ◽  
Immediate Early ◽  
Productive Infection ◽  
Mrna Stabilization ◽  
Early Protein ◽  
Host Shutoff ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT Herpes simplex virus (HSV) stifles cellular gene expression during productive infection of permissive cells, thereby diminishing host responses to infection. Host shutoff is achieved largely through the complementary actions of two viral proteins, ICP27 and virion host shutoff (vhs), that inhibit cellular mRNA biogenesis and trigger global mRNA decay, respectively. Although most cellular mRNAs are thus depleted, some instead increase in abundance after infection; perhaps surprisingly, some of these contain AU-rich instability elements (AREs) in their 3′-untranslated regions. ARE-containing mRNAs normally undergo rapid decay; however, their stability can increase in response to signals such as cytokines and virus infection that activate the p38/MK2 mitogen-activated protein kinase (MAPK) pathway. We and others have shown that HSV infection stabilizes the ARE mRNA encoding the stress-inducible IEX-1 mRNA, and a previous report from another laboratory has suggested vhs is responsible for this effect. However, we now report that ICP27 is essential for IEX-1 mRNA stabilization whereas vhs plays little if any role. A recent report has documented that ICP27 activates the p38 MAPK pathway, and we detected a strong correlation between this activity and stabilization of IEX-1 mRNA by using a panel of HSV type 1 (HSV-1) isolates bearing an array of previously characterized ICP27 mutations. Furthermore, IEX-1 mRNA stabilization was abrogated by the p38 inhibitor SB203580. Taken together, these data indicate that the HSV-1 immediate-early protein ICP27 alters turnover of the ARE-containing message IEX-1 by activating p38. As many ARE mRNAs encode proinflammatory cytokines or other immediate-early response proteins, some of which may limit viral replication, it will be of great interest to determine if ICP27 mediates stabilization of many or all ARE-containing mRNAs.

The cellular transcription factor USF cooperates with varicella-zoster virus immediate-early protein 62 to symmetrically activate a bidirectional viral promoter

1994 ◽  
Vol 14 (10) ◽  
pp. 6896-6906 ◽  
Author(s):  
J L Meier ◽  
X Luo ◽  
M Sawadogo ◽  
S E Straus
Keyword(s):  
Dna Binding ◽  
Varicella Zoster Virus ◽  
Dominant Negative ◽  
Immediate Early ◽  
Activation Process ◽  
Viral Promoter ◽  
Varicella Zoster ◽  
Cellular Transcription Factor ◽  
Early Protein ◽  
Target Promoters

The mechanisms governing the function of cellular USF and herpesvirus immediate-early transcription factors are subjects of considerable interest. In this regard, we identified a novel form of coordinate gene regulation involving a cooperative interplay between cellular USF and the varicella-zoster virus immediate-early protein 62 (IE 62). A single USF-binding site defines the potential level of IE 62-dependent activation of a bidirectional viral early promoter of the DNA polymerase and major DNA-binding protein genes. We also report a dominant negative USF-2 mutant lacking the DNA-binding domain that permits the delineation of the biological role of both USF-1 and USF-2 in this activation process. The symmetrical stimulation of the bidirectional viral promoter by IE 62 is achieved at concentrations of USF-1 (43 kDa) or USF-2 (44 kDa) already existing in cells. Our observations support the notion that cellular USF can intervene in and possibly target promoters for activation by a herpesvirus immediate-early protein.

Serum proteolytic activity during the growth of C6 astrocytoma

1992 ◽  
Vol 77 (4) ◽  
pp. 595-600 ◽  
Author(s):  
Indrasen S. Vaithilingam ◽  
Warren McDonald ◽  
Noel K. Brown ◽  
Eric Stroude ◽  
Robert A. Cook ◽  
...  
Keyword(s):  
Proteolytic Activity ◽  
Type Iv Collagen ◽  
Collagenase Activity ◽  
Type Iv Collagenase ◽  
Content Type ◽  
Type Iv ◽  
Astrocytoma Cells ◽  
Vessel Remodeling ◽  
C6 Astrocytoma ◽  
Fine Print

✓ Tumor growth is dependent on the ability of neoplastic cells to induce angiogenesis. Blood-vessel remodeling requires the reconstruction of the nonfibrous proteins and type IV collagen components of the basement membrane. This study has assessed the influence of the growth of C6 astrocytoma cells in the rat spheroid implantation model on serum general protease and type IV collagenase activity. The results demonstrate that general protease activity increased in serum, reaching maximum values on Day 6 and Day 13 following spheroid implantation, and that type IV collagenase activity increased in serum, obtaining maximum values on Day 8 and Day 15. The measurement of serum proteolytic activity may be of value in the detection of recurrent tumors.

scholarly journals Human Cytomegalovirus Immediate-Early Protein IE2 Tethers a Transcriptional Repression Domain to p53

1996 ◽  
Vol 271 (7) ◽  
pp. 3534-3540 ◽  
Author(s):  
Hsiu-Lan Tsai ◽  
Guang-Hsiung Kou ◽  
Shan-Chun Chen ◽  
Cheng-Wen Wu ◽  
Young-Sun Lin
Keyword(s):  
Human Cytomegalovirus ◽  
Transcriptional Repression ◽  
Immediate Early ◽  
Early Protein ◽  
Repression Domain

scholarly journals Impaired development of the cerebellum in transgenic mice expressing the immediate-early protein IE180 of pseudorabies virus

Virology ◽  
2003 ◽  
Vol 307 (2) ◽  
pp. 243-254 ◽  
Author(s):  
Satoshi Taharaguchi ◽  
Yasuhiro Kon ◽  
Saori Yoshino ◽  
Etsuro Ono
Keyword(s):  
Transgenic Mice ◽  
Pseudorabies Virus ◽  
Immediate Early ◽  
Early Protein
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