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Molecular programming of endothelin‐1 in HIV‐infected brain: role of Tat in up‐regulation of ET‐1 and its inhibition by statins
Author(s) -
Chauhan Ashok,
Hahn Sven,
Gartner Suzanne,
Pardo Carlos A.,
Netesan Senthil Kumar,
McArthur Justin,
Nath Avindra
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.06-7054com
Subject(s) - astrocyte , biology , immunology , virology , microbiology and biotechnology , central nervous system , neuroscience
Human Immune Deficiency Virus‐1 (HIV‐1) infection can induce severe and debilitating neurological problems, including behavioral abnormalities, motor dysfunction, and dementia. HIV can per‐sistently infect astrocytes, during which viral accessory proteins are produced that are unaffected by current antiretroviral therapy. The effect of these proteins on astrocyte function remains unknown. Astrocytes are the predominant cells within the brain; thus, disruption of astrocyte function could influence the neuropathogenesis of HIV infection. To explore further these effects, we constitutively expressed HIV‐Tat protein in astrocytes. Since the nuclear presence of Tat protein leads to alteration of host gene expression, we further analyzed the effects of Tat on host gene transcripts. Endothe‐lin‐1 (ET‐1) was a significantly elevated transcript as verified by reverse transcription‐polymerase chain reaction (RT‐PCR), and it was subsequently released extra‐cellularly in Tat‐expressing and HIV‐infected astrocytes. ET‐1 expression was also prominent in reactive astrocytes and neurons in brain tissues from basal ganglia and frontal lobes of HIV encephalitic patients. HIV‐Tat regulated ET‐1 at the transcriptional level through NF‐κB (NF‐κB)‐responsive sites in the ET‐1 promoter. Intriguingly, simvastatin (10 μM) down‐regulated HrV‐Tat‐induced ET‐1 and also inhibited activation of NF‐κB in astrocytes. Our findings suggest that ET‐1 may be critical in mediating the neuropathogenesis of HIV dementia and that statins may have therapeutic potential in these patients.—Chauhan, A., Hahn, S., Gartner, S., Pardo, C. A., Netesan, S. K., McArthur, J., Nath, A. Molecular programming of endothelin‐1 in HIV‐infected brain: role of Tat in up‐regulation of ET‐1 and its inhibition by statins. FASEB J. 21, 777–789 (2007)