Impaired astrocytes and diffuse activation of microglia in the cerebral cortex in simian immunodeficiency virus-infected Macaques without simian immunodeficiency virus encephalitis.
Various types of neuronal damage have been reported in acquired immunodeficiency syndrome (AIDS) dementia. We previously demonstrated that inflammation and cortical damage occur independently according to viral tropism in a simian immunodeficiency virus (SIV)-infected macaque model of AIDS dementia. To elucidate the pathogenesis of cortical degeneration, we examined the frontal cortex of SIV-infected macaques and found apoptosis and decreased expression of the excitatory amino acid transporter 2 in astrocytes and diffuse activation of microglia in association with limited neuronal damage. Some activated microglia also expressed excitatory amino acid transporter 2 but not proinflammatory cytokines. No inflammatory changes were seen in the cortex or the white matter, and SIV-infected cells were not detected in or around cortical lesions either by immunohistochemistry or by the polymerase chain reaction detection of SIV genomes of extracted DNA from microdissected tissue samples. These results indicate that an astrocytic abnormality and a compensatory activation of microglia might provide a protective effect against neuronal degeneration in the frontal cortex of SIV-infected macaques without SIV encephalitis.
Division of Molecular Pathology, Center for Chronic Viral Diseases, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan.
Hui Qin
HQ
Xing
Kazuyasu
K
Mori
Chie
C
Sugimoto
Fumiko
F
Ono
Kimiko
K
Izumo
Ryuji
R
Kuboda
Shuji
S
Izumo
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D001253:Astrocytes / Q000473:pathology; D002540:Cerebral Cortex / Q000276:immunology / Q000473:pathology* / Q000821:virology; D004660:Encephalitis / Q000473:pathology; D027342:Excitatory Amino Acid Transporter 2 / Q000096:biosynthesis; D005260:Female; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D008251:Macaca; D008297:Male; D017628:Microglia / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D016097:Simian Acquired Immunodeficiency Syndrome / Q000276:immunology / Q000473:pathology* / Q000821:virology; D015302:Simian Immunodeficiency Virus; D019562:Viral Load
D027342:Excitatory Amino Acid Transporter 2