Tau‐positive dial Inclusions in Progressive Supranuclear Palsy, Corticobasal Degeneration and Pick's Disease

Abstract

The presence of tau-positive glial inclusions has been recently found a consistent feature in the brains of patients with progressive supranuclear palsy (PSP), corticobasal degeneration (CBD) and Pick's disease (PiD). These inclusions are classified based on cellular origin as tau-positive astrocytes, presumably either fibrillary or protoplasmic, coiled bodies and glial threads. Immunohistochemically, their major structural component is abnormal tau proteins, similar to those found in Alzheimer's disease. Nevertheless, their morphology, including ultrastructural profile, has been suggested to be distinctive for each disease. The profile and extent of particular glial inclusions correlate well with disease phenotype. Highly characteristic correlations include tufts of abnormal fibers in PSP, astrocytic plaques and dense glial threads in CBD and ramified astrocytes and small Pick body-like inclusions in PiD. The significance of the inclusions in disease pathogenesis and their biochemical characteristics remain to be clarified. Nevertheless, these distinctive glial lesions most likely reflect fundamental alterations in isoform composition of tau as well as its specific cellular and regional expression in sporadic tauopathies.

Argyrophilic thorny astrocyte clusters in association with Alzheimer’s disease pathology in possible primary progressive aphasia

“…The constituent thorny astrocytes are a subtype of glial Wbrillary tangles (GFT), argyrophilic masses containing deposits of abnormal tau proteins located in the cytoplasm of glial cells [37]. Electron microscopy typically shows bundles of 15 nm straight tubules [22].…”

“…Tufted astrocytes are considered pathognomonic of PSP [19,67], and glial plaques are characteristic of CBD [8,37,38,2],…”

Spatial patterns of the tau pathology in progressive supranuclear palsy

“…Abnormally enlarged neurons (EN) are present, especially in the inferior olivary nucleus [10] and throughout the neocortex [17]. In addition, 'tufted' astrocytes (TA) and glial inclusions (GI) ('coiled bodies') [18][19][20] are present in the motor cortex and striatum [14]. The presence of TA is often regarded as diagnostic for PSP [19] and distinguishes the disorder from the closely-related CBD [21].…”

Glial cell inclusions and the pathogenesis of neurodegenerative diseases

“…However, it is tempting to speculate that glia make active contributions to neuronal cell death in diseases other than ALS, and experiments designed to address this hypothesis are eagerly awaited. Chin and Goldman, 1996;Komori, 1999;Dickson, 2004 AD and Aging Subpial and subependymal regions Sporadic, tau protein Tau-positive astrocytes (thorn-shaped astrocytes) Ikeda et al, 1995;Chin and Goldman, 1996 Familial PD/DLBD Limbic lobe, basal ganglia and brainstem …”