Abstract
To analyze neurodegeneration in brain cortex samples from human immunodeficiency virus
(HIV)-vertically-infected children diagnosed with progressive or static HIV-encephalopathy.
We performed a descriptive retrospective and cross-sectional study on 15 HIV-infected
children. Eight children were diagnosed with progressive-encephalopathy (EP) and seven
with static-EP. Autopsy samples of the frontal cortex from the 15 children were studied.
Apoptotic analysis was performed by an assay, which detects apoptotic cells by labeling
the fragmentation of DNA by TdT – mediated dUTP nick end labeling (TUNEL) assay. The
presence of phosphorylated p53 (p53Ser46P) indicates the beginning of the cell death
process. Glial fibrillary acidic protein a marker for glial cells, and p53Ser46P were
detected by immunohistochemical assays. All samples from the 15 HIV-infected children
showed positive results using TUNEL and showed an increase in p53Ser46P. However,
the number of apoptotic cells was higher in samples from children with progressive-EP
and was comprised of a higher number of dying neurons than dying glial cells. In contrast,
glial cells were more affected in children with static-EP. We observed gliosis (abnormal
proliferation of astrocytes in damaged areas of the brain) in all samples, but in
the static-EP samples, gliosis was observed in areas close to blood vessels, and it
was more pronounced than in progressive-EP samples. Our results suggest that depending
whether the diagnosis is progressive-EP or static-EP, neural affliction activates
programmed cell death in brain tissue of HIV-infected children. Moreover, there are
differences in the type of cellular population affected as well as in the level of
glial cell activation.
Keywords
Children - HIV-encephalopathy - central nervous system - apoptosis - p53 - glial activation
