XIAP immunoreactivity in glial and neuronal cytoplasmic inclusions in multiple system atrophy

• Published in: Clinical neuropathology Vol. 33; no. 1; p. 76
• Main Authors: Kawamoto, Yasuhiro, Ito, Hidefumi, Ihara, Masafumi, Takahashi, Ryosuke
• Format: Journal Article
• Language: English
• Published: Germany 01.01.2014
• Subjects: Aged; Case-Control Studies; Female; High-Temperature Requirement A Serine Peptidase 2; Humans; Inclusion Bodies - metabolism; Inclusion Bodies - pathology; Male; Middle Aged; Mitochondrial Proteins - metabolism; Multiple System Atrophy - etiology; Multiple System Atrophy - metabolism; Multiple System Atrophy - pathology; Neuroglia - metabolism; Neuroglia - pathology; Serine Endopeptidases - metabolism; X-Linked Inhibitor of Apoptosis Protein - metabolism
• ISSN: 0722-5091
• DOI: 10.5414/NP300610

X-linked inhibitor of apoptosis protein (XIAP) selectively binds to caspases-3, -7 and -9, and inhibits the activities of these caspases. To elucidate the role of XIAP in patients with multiple system atrophy (MSA), we performed immunohistochemical studies on XIAP in formalin-fixed, paraffin-embedded sections from 8 normal subjects and 10 patients with MSA. In normal brains, several types of neurons were immunostained for XIAP, and XIAP-immunopositive oligodendrocytes were scattered throughout the cerebral and cerebellar white matter. In the MSA brains, neuronal XIAP immunoreactivity was spared even in the severely-affected lesions, and glial cytoplasmic inclusions (GCIs), neuronal cytoplasmic inclusions (NCIs) and dystrophic neurites were all intensely immunoreactive for XIAP. A semiquantitative analysis of mid-pons sections double-immunostained for XIAP and α-synuclein demonstrated that the average percentages of XIAP-immunopositive GCIs and NCIs in the pontine nucleus were 70.2% and 82.2%, respectively. Our results suggest that a widespread accumulation of XIAP may occur in brains with MSA, and that XIAP may be partially associated with the pathogenesis of MSA.