Suppression of HIV-1 Tat-induced monocyte adhesiveness by a cell-permeable superoxide dismutase in astrocytes

Abstract

HIV-1 Tat is considered to be one of key players to facilitate monocyte entry into the CNS, which is characteristic feature of AIDS-related encephalitis and dementia. This study was performed to determine the regulatory function of superoxide dismutase (SOD) on the HIV-1 Tat

Extracellular HIV-1 Tat up-regulates expression of matrix metalloproteinase-9 via a MAPK-NF-κB dependent pathway in human astrocytes

“…The MAPKs such as p38, JNK and ERK protein kinase are the principal components in the signaling cascades leading to activation of NF-κB upon various stimuli. Previous studies have shown that extracellular HIV-1 Tat can regulate the activity of MAPKs in astrocytes (Kutsch et al, 2000;Song et al, 2007a). MAPK inhibitors suppressed Tat-induced mRNA and protein expression of MMP-9 as well as gelatinolytic activity of MMP-9 ( Figure 3B).…”

“…Previous studies have indicated that extracellular HIV-1 Tat has a regulatory effect on the activity of MAPKs such as p38, JNK and ERK protein kinase in astrocytes (Kutsch et al, 2000, Song et al, 2007a. To examine HIV-1 Tat-induced MAPK activation, CRT-MG cells were exposed to HIV-1 Tat (500 ng/ml) for various times, and then MAPK activation was analyzed by Western blot analysis using phospho-specific antibodies against MAPK proteins.…”

Antioxidant enzyme dysfunction in monocytes and CSF of Hispanic women with HIV-associated cognitive impairment

“…Another aspect of low Cu/Zn SOD function is altered monocyte chemotaxis. Cu/Zn SOD controls up-regulation of adhesion proteins by HIV-1 Tat-mediated reactive oxygen species (ROS) release in monocytes (Song et al, 2007). Moreover, unrestricted ROS production may facilitate NF-κβ induction, subsequent HIV long terminal repeat transactivation, and chronic viral replication upon cell maturation into macrophages (Israel and Gougerot-Pocidalo, 1997).…”

Differential regulation of inducible nitric oxide synthase and cyclooxygenase-2 expression by superoxide dismutase in lipopolysaccharide stimulated RAW 264.7 cells

“…RAW 264.7 cells were treated with LPS (100 ng/ml) for 30 min, then nuclear extracts of cells were prepared and analyzed for NF-κB binding activity, as described previously (Song et al, 2007). Five micrograms of nuclear extracts were equilibrated for 15 min in binding buffer (10 mM Tris-HCl, pH 8.0, 75 mM KCl, 2.5 mM MgCl2, 0.1 mM EDTA, 10% glycerol, 0.25 mM DTT) and 1 μg of poly dI/dC.…”