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Synaptic proteins linked to HIV-1 infection and immunoproteasome induction: proteomic analysis of human synaptosomes.

Gelman BB, Nguyen TP - J Neuroimmune Pharmacol (2009)

Bottom Line: Synapsin 1b and stathmin were inversely related to brain HIV-1 load; 14-3-3zeta and 14-4-4epsilon proteins were higher in subjects with HIV-1 loads.Perturbed synaptosome proteins were linked with IPS subunit composition, and 14-3-3zeta was histologically colocalized with IPS subunits in stained neocortical neurons.Proteomics illustrates that certain human proteins within the synaptic compartment are involved with changes in the synaptodendritic arbor and neurocognitive impairment in HIV-1-infected people.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, USA. bgelman@utmb.edu

ABSTRACT
Infection of the central nervous system with human immunodeficiency virus type 1 (HIV-1) can produce morphological changes in the neocortical synaptodendritic arbor that are correlated with neurocognitive impairment. To determine whether HIV-1 infection influences the protein composition of human synapses, a proteomic study of isolated nerve endings was undertaken. Synaptosomes from frontal neocortex were isolated using isopyknic centrifugation from 19 human brain specimens. Purity and enrichment were assessed by measuring pre- and postsynaptic protein markers. Two-dimensional polyacrylamide gel electrophoresis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry was used to screen for proteins differentially expressed in HIV/AIDS. The concentrations of 31 candidate protein spots were potentially abnormal in HIV-infected decedents with HIV encephalitis and/or increased expression of immunoproteasome subunits. Immunoblots showed that the concentration of some of them was related to HIV-1 infection of the brain and immunoproteasome (IPS) induction. Synapsin 1b and stathmin were inversely related to brain HIV-1 load; 14-3-3zeta and 14-4-4epsilon proteins were higher in subjects with HIV-1 loads. Perturbed synaptosome proteins were linked with IPS subunit composition, and 14-3-3zeta was histologically colocalized with IPS subunits in stained neocortical neurons. Proteomics illustrates that certain human proteins within the synaptic compartment are involved with changes in the synaptodendritic arbor and neurocognitive impairment in HIV-1-infected people.

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Confocal immunofluorescence microscopy for 14-3-3ζ (red) and the immunoproteasome subunit marker LMP2 (green) in a subject with HIV encephalitis and high concentrations of these proteins in the synaptosome preparation. Punctate deposits of both proteins outline the distinct shape of a pyramidal neocortical neuron and surrounding neuropil. The perikaryon and neuropil both contain deposits of these proteins, which morphologically resemble synaptic densities. Arrows in the large bottom panel denote foci where the antigens are colocalized in the merged image. Attempts to localize synapsin 1 were not successful technically because its concentration was sharply decreased in HIV encephalitis. Scale bar = 10 μm
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Fig3: Confocal immunofluorescence microscopy for 14-3-3ζ (red) and the immunoproteasome subunit marker LMP2 (green) in a subject with HIV encephalitis and high concentrations of these proteins in the synaptosome preparation. Punctate deposits of both proteins outline the distinct shape of a pyramidal neocortical neuron and surrounding neuropil. The perikaryon and neuropil both contain deposits of these proteins, which morphologically resemble synaptic densities. Arrows in the large bottom panel denote foci where the antigens are colocalized in the merged image. Attempts to localize synapsin 1 were not successful technically because its concentration was sharply decreased in HIV encephalitis. Scale bar = 10 μm

Mentions: Morphological localization with immunoproteasomes To determine whether the altered synaptosomal proteins in HIV/AIDS are histologically related to IPS subunits, we performed dual localization using laser confocal microscopy. Immunoreactivities of 14-3-3ζ and the IPS subunit LMP2 both were present in punctate neuronal and neuropil markings that were typical of neocortical synapses. Colocalization of 14-3-3ζ and LMP2 in these punctate synaptic deposits was often observed (Fig. 3). Colocalizing proteins were most obvious in the brains that contained a high HIV RNA concentration and HIVE. It was not possible to demonstrate a spatial relationship using synapsin 1b staining because its concentration was sharply depressed due to HIV-1 and difficult to detect histochemically (not illustrated).Fig. 3


Synaptic proteins linked to HIV-1 infection and immunoproteasome induction: proteomic analysis of human synaptosomes.

Gelman BB, Nguyen TP - J Neuroimmune Pharmacol (2009)

Confocal immunofluorescence microscopy for 14-3-3ζ (red) and the immunoproteasome subunit marker LMP2 (green) in a subject with HIV encephalitis and high concentrations of these proteins in the synaptosome preparation. Punctate deposits of both proteins outline the distinct shape of a pyramidal neocortical neuron and surrounding neuropil. The perikaryon and neuropil both contain deposits of these proteins, which morphologically resemble synaptic densities. Arrows in the large bottom panel denote foci where the antigens are colocalized in the merged image. Attempts to localize synapsin 1 were not successful technically because its concentration was sharply decreased in HIV encephalitis. Scale bar = 10 μm
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2824116&req=5

Fig3: Confocal immunofluorescence microscopy for 14-3-3ζ (red) and the immunoproteasome subunit marker LMP2 (green) in a subject with HIV encephalitis and high concentrations of these proteins in the synaptosome preparation. Punctate deposits of both proteins outline the distinct shape of a pyramidal neocortical neuron and surrounding neuropil. The perikaryon and neuropil both contain deposits of these proteins, which morphologically resemble synaptic densities. Arrows in the large bottom panel denote foci where the antigens are colocalized in the merged image. Attempts to localize synapsin 1 were not successful technically because its concentration was sharply decreased in HIV encephalitis. Scale bar = 10 μm
Mentions: Morphological localization with immunoproteasomes To determine whether the altered synaptosomal proteins in HIV/AIDS are histologically related to IPS subunits, we performed dual localization using laser confocal microscopy. Immunoreactivities of 14-3-3ζ and the IPS subunit LMP2 both were present in punctate neuronal and neuropil markings that were typical of neocortical synapses. Colocalization of 14-3-3ζ and LMP2 in these punctate synaptic deposits was often observed (Fig. 3). Colocalizing proteins were most obvious in the brains that contained a high HIV RNA concentration and HIVE. It was not possible to demonstrate a spatial relationship using synapsin 1b staining because its concentration was sharply depressed due to HIV-1 and difficult to detect histochemically (not illustrated).Fig. 3

Bottom Line: Synapsin 1b and stathmin were inversely related to brain HIV-1 load; 14-3-3zeta and 14-4-4epsilon proteins were higher in subjects with HIV-1 loads.Perturbed synaptosome proteins were linked with IPS subunit composition, and 14-3-3zeta was histologically colocalized with IPS subunits in stained neocortical neurons.Proteomics illustrates that certain human proteins within the synaptic compartment are involved with changes in the synaptodendritic arbor and neurocognitive impairment in HIV-1-infected people.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, USA. bgelman@utmb.edu

ABSTRACT
Infection of the central nervous system with human immunodeficiency virus type 1 (HIV-1) can produce morphological changes in the neocortical synaptodendritic arbor that are correlated with neurocognitive impairment. To determine whether HIV-1 infection influences the protein composition of human synapses, a proteomic study of isolated nerve endings was undertaken. Synaptosomes from frontal neocortex were isolated using isopyknic centrifugation from 19 human brain specimens. Purity and enrichment were assessed by measuring pre- and postsynaptic protein markers. Two-dimensional polyacrylamide gel electrophoresis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry was used to screen for proteins differentially expressed in HIV/AIDS. The concentrations of 31 candidate protein spots were potentially abnormal in HIV-infected decedents with HIV encephalitis and/or increased expression of immunoproteasome subunits. Immunoblots showed that the concentration of some of them was related to HIV-1 infection of the brain and immunoproteasome (IPS) induction. Synapsin 1b and stathmin were inversely related to brain HIV-1 load; 14-3-3zeta and 14-4-4epsilon proteins were higher in subjects with HIV-1 loads. Perturbed synaptosome proteins were linked with IPS subunit composition, and 14-3-3zeta was histologically colocalized with IPS subunits in stained neocortical neurons. Proteomics illustrates that certain human proteins within the synaptic compartment are involved with changes in the synaptodendritic arbor and neurocognitive impairment in HIV-1-infected people.

Show MeSH
Related in: MedlinePlus