Role of ß-catenin and TCF/LEF family members in transcriptional activity of HIV in astrocytes.
J Virol
; 86(4): 1911-21, 2012 Feb.
Article
en En
| MEDLINE
| ID: mdl-22156527
ABSTRACT
The Wnt/ß-catenin pathway is involved in diverse cell functions governing development and disease. ß-Catenin, a central mediator of this pathway, binds to members of the TCF/LEF family of transcription factors to modulate hundreds of genes. Active Wnt/ß-catenin/TCF-4 signaling plays a significant role in repression of HIV-1 replication in multiple cell targets, including astrocytes. To determine the mechanism by which active ß-catenin/TCF-4 leads to inhibition of HIV replication, we knocked down ß-catenin or TCF/LEF members in primary astrocytes and astrocytomas transiently transfected with an HIV long terminal repeat (LTR)-luciferase reporter that contained an integrated copy of the HIV LTR-luciferase construct. Knockdown of either ß-catenin or TCF-4 induced LTR activity by 2- to 3-fold under both the episomal and integrated conditions. This knockdown also increased presence of serine 2-phosphorylated RNA polymerase II (Pol II) on the HIV LTR as well as enhanced its processivity. Knockdown of ß-catenin/TCF-4 also impacted tethering of other transcription factors on the HIV promoter. Specifically, knockdown of TCF-4 enhanced binding of C/EBPß, C/EBPδ, and NF-κB to the HIV LTR, while ß-catenin knockdown increased binding of C/EBPß and C/EBPδ but had no effect on NF-κB. Approximately 150 genes in astrocytes were impacted by ß-catenin knockdown, including genes involved in inflammation/immunity, uptake/transport, vesicular transport/exocytosis, apoptosis/cellular stress, and cytoskeleton/trafficking. These findings indicate that modulation of the ß-catenin/TCF-4 axis impacts the basal level of HIV transcription in astrocytes, which may drive low level/persistent HIV in astrocytes that can contribute to ongoing neuroinflammation, and this axis also has profound effects on astrocyte biology.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Factores de Transcripción
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Infecciones por VIH
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Activación Transcripcional
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Astrocitos
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VIH-1
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Beta Catenina
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Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice
Límite:
Humans
Idioma:
En
Revista:
J Virol
Año:
2012
Tipo del documento:
Article
País de afiliación:
Estados Unidos