Extracellular HIV-1 Tat enhances monocyte adhesion by up-regulation of ICAM-1 and VCAM-1 gene expression via ROS-dependent NF-kappaB activation in astrocytes
Experimental & Molecular Medicine
;
: 27-37, 2007.
Article
in English
| WPRIM
| ID: wpr-37558
ABSTRACT
One of characteristic features of AIDS-related encephalitis and dementia is the infiltration of monocytes into the CNS. HIV-1 Tat was demonstrated to facilitate monocyte entry into the CNS. In this study, we examined the effect of HIV-1 Tat on the expression of adhesion molecules, generation of reactive oxygen species (ROS) and NF-kappaB activation in CRT-MG human astroglioma cells. Treatment of CRT-MG cells with HIV-1 Tat protein significantly increased protein and mRNA levels of ICAM-1 and VCAM-1, as measured by Western blot analysis and RT-PCR, indicating that Tat increases these protein levels at an mRNA level. In addition, Tat induced the activation of NF-kappaB in astrocytes. Treatment of CRT-MG with NF-kappaB inhibitors led to decrease in Tat-induced protein and mRNA expression of ICAM-1 and VCAM-1. Furthermore, HIV-1 Tat protein increased ROS generation. Inhibition of Tat-induced ROS generation by N-acetyl cysteine, vitamin C and diphenyl iodonium suppressed Tat-induced NF-kappaB activation, ICAM-1 and VCAM-1 expression, and monocyte adhesion in CRT-MG. These data indicate that HIV-1 Tat can modulate monocyte adhesiveness by increasing expression of adhesion molecules such as ICAM-1 and VCAM-1 via ROS- and NF-kappaB-dependent mechanisms in astrocytes.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Transcription, Genetic
/
Monocytes
/
Gene Products, tat
/
Cell Adhesion
/
Up-Regulation
/
Cell Line
/
Astrocytes
/
NF-kappa B
/
HIV-1
/
Reactive Oxygen Species
Limits:
Humans
Language:
English
Journal:
Experimental & Molecular Medicine
Year:
2007
Type:
Article
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