Glial intranuclear inclusion bodies in a patient with Alzheimer's disease

Inclusion-positive cell types in adult-onset intranuclear inclusion body disease: implications for clinical diagnosis

The distribution of inclusions in adult-onset type intranuclear inclusion body disease (INIBD) has not been fully described. We analyzed the clinical and pathological changes of three autopsy cases of adult type INIBD and provide a detailed description of the distribution of inclusions in nervous system and visceral organs. Although patients showed cognitive decline and autonomic dysfunction, there were no specific symptoms related to general organs. The neuropathological changes responsible for cognitive decline and autonomic dysfunction were considered to be white matter changes in the cerebral hemispheres and inclusions in the autonomic nervous system, e.g., in the sympathetic ganglia and myenteric plexus. Alterations of spongiosis with both myelin and axon loss in the cerebral white matter seemed to be related to dysfunction of astrocytes with intranuclear inclusions. In visceral organs, the inclusions were much more widely distributed than previously appreciated and included renal mesangial cells, adrenal sustentacular cells, fibrocytes, Kupffer cells, pancreatic centroacinar and ductal epithelial cells. Since skeletal muscle cells, Schwann cells and smooth muscle cells were also inclusion positive, we propose that biopsy of muscle, peripheral nerve or rectum may prove useful for the clinical diagnosis of INIBD.

Nuclear bodies in neurodegenerative disease

Neurodegenerative diseases are characterized by a relentlessly progressive loss of the functional and structural integrity of the central nervous system. In many cases, these diseases arise sporadically and the causes are unknown. The abnormal aggregation of protein within the cytoplasm or the nucleus of brain cells represents a unifying pathological feature of these diseases. There is increasing evidence for nuclear dysfunction in neurodegenerative diseases. How this relates to protein aggregation in the context of "cause and effect" remains to be determined in most cases. Co-ordinated nuclear function is predicated on the activity of distinct nuclear subdomains, or nuclear bodies, each responsible for a specific function. If nuclear dysfunction represents an important etiopathological feature in neurodegenerative disease, then this should be reflected by functional and/or morphological alterations in this nuclear compartmentalization. For most neurodegenerative diseases, evidence for nuclear dysfunction, with attendant consequences for nuclear architecture, is only beginning to emerge. In this review, I will discuss neurodegenerative diseases in the context of nuclear dysfunction and, more specifically, alterations in nuclear bodies. Although research in this field is in its infancy, identifying alterations in the nucleus in neurodegenerative disease has potentially profound implications for elucidating the pathogenesis of these disorders.

Abnormalities of the nucleus and nuclear inclusions in neurodegenerative disease: a work in progress

Neurodegenerative diseases are characterized pathologically by the abnormal accumulation of pathogenic protein species within the cell. Several neurodegenerative diseases feature intranuclear protein aggregation in the form of intranuclear inclusion bodies. Studies of these intranuclear inclusions are providing important clues regarding the cellular pathophysiology of these diseases, as exemplified by recent progress in defining the genetic basis of a subset of frontotemporal dementia cases. The precise role of intranuclear inclusion bodies in disease pathogenesis is currently a focus of debate. The present review provides an overview of the diverse family of neurodegenerative diseases in which nuclear inclusions form part of the neuropathological spectrum. In addition, current pathogenetic concepts relevant to these diseases will be reviewed and arguments for and against a protective role for intranuclear inclusions will be presented. The relationship of pathological intranuclear inclusions to functional intranuclear bodies will also be discussed. Finally, by analogy with pathological intranuclear inclusions, I will speculate on the possibility that intranuclear protein aggregation may represent a constitutive cellular protective mechanism occurring in neurons under physiological conditions.