Proteomics analysis of human astrocytes expressing the HIV protein Tat.
Astrocyte infection in HIV has been associated with rapid progression of dementia in a subset of HIV/AIDS patients. Astrogliosis and microglial activation are observed in areas of axonal and dendritic damage in HIVD. In HIV-infected astrocytes, the regulatory gene tat is over expressed and mRNA levels for Tat are elevated in brain extracts from individuals with HIV-1 dementia. Tat can be detected in HIV-infected astrocytes in vivo. The HIV-1 protein Tat transactivates viral and cellular gene expression, is actively secreted mainly from astrocytes, microglia and macrophages, into the extracellular environment, and is taken up by neighboring uninfected cells such as neurons. The HIV-1 protein Tat released from astrocytes reportedly produces trimming of neurites, mitochondrial dysfunction and cell death in neurons, while protecting its host, the astrocyte. We utilized proteomics to investigate protein expression changes in human astrocytes intracellularly expressing Tat (SVGA-Tat). By coupling 2D fingerprinting and identification of proteins by mass spectrometry, we identified phosphatase 2A, isocitrate dehydrogenase, nuclear ribonucleoprotein A1, Rho GDP dissociation inhibitor alpha, beta-tubulin, crocalbin like protein/calumenin, and vimentin/alpha-tubulin to have decreased protein expression levels in SVGA-Tat cells compared to the SVGA-pcDNA cells. Heat shock protein 70, heme oxygenase-1, and inducible nitric oxide synthase were found to have increased protein expression in SVGA-Tat cells compared to controls by slotblot technique. These findings are discussed with reference to astrocytes serving as a reservoir for the HIV virus and how Tat promotes survival of the astrocytic host.
Pocernich
Chava B
CB
Department of Chemistry and Center of Membrane Sciences, 125 Chemistry-Physics Building, University of Kentucky, Lexington, KY 40506, USA.
Boyd-Kimball
Debra
D
Poon
H Fai
HF
Thongboonkerd
Visith
V
Lynn
Bert C
BC
Klein
Jon B
JB
Calebrese
Vittorio
V
Nath
Avindra
A
Butterfield
D Allan
DA
D000704:Analysis of Variance; D001253:Astrocytes / Q000378:metabolism* / Q000821:virology; D002460:Cell Line; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D005786:Gene Expression Regulation / Q000502:physiology*; D015696:Gene Products, tat / Q000378:metabolism*; D015658:HIV Infections / Q000378:metabolism*; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism; D051547:Heme Oxygenase-1; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D008565:Membrane Proteins; D019001:Nitric Oxide Synthase / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D040901:Proteomics; D054322:tat Gene Products, Human Immunodeficiency Virus
D015696:Gene Products, tat; D018840:HSP70 Heat-Shock Proteins; D008565:Membrane Proteins; D054322:tat Gene Products, Human Immunodeficiency Virus; C496319:NOS2 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496541:HMOX1 protein, human; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1