Affiliations: Department of Laboratorio Inmuno-Biología
Molecular, Hospital General Universitario Gregorio Marañón, Madrid,
Spain | National Institute for Infectious Diseases IRCCS "L.
Spallanzani", Rome, Italy | Department of Pathology, Children's Hospital Bambino
Gesù, Rome, Italy | Department of Biology, University of Rome "Tor
Vergata", Rome, Italy | CIBER de Bioquímica, Biomateriales y
Nanomedicina, Instituto Salud Carlos III, Zaragoza, Spain
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