Unusual, rod-shaped cytoplasmic inclusions (Hirano bodies) in a cerebellar hemangioblastoma

Revisiting the relevance of Hirano bodies in neurodegenerative diseases

AIMS

Hirano bodies (HBs) are eosinophilic pathological structures with two morphological phenotypes commonly found in the hippocampal CA1 region in Alzheimer's disease (AD). This study evaluated the prevalence and distribution of HBs in AD and other neurodegenerative diseases.

METHODS

This cross-sectional study systematically evaluated HBs in a cohort of 193 cases with major neurodegenerative diseases, including AD (n = 91), Lewy body disease (LBD, n = 87), progressive supranuclear palsy (PSP, n = 36), multiple system atrophy (MSA, n = 14) and controls (n = 26). The prevalence, number and morphology of HBs in the stratum lacunosum (HBL) and CA1 pyramidal cell layer were examined. In addition, we investigated the presence of HBs in five additional hippocampal subregions.

RESULTS

The morphological types of HBs in CA1 were divided into three, including a newly discovered type, and were evaluated separately, with their morphology confirmed in three dimensions: (1) classic rod-shaped HB (CHB), (2) balloon-shaped HB (BHB) and the newly described (3) string-shaped HB (SHB). The prevalence of each HB type differed between disease groups: Compared with controls, for CHB in AD, AD + LBD, PSP and corticobasal degeneration, for BHB in AD + LBD and PSP, and SHB in AD + LBD and PSP were significantly increased. Regression analysis showed that CHBs were independently associated with higher Braak NFT stage, BHBs with LBD and TDP-43 pathology, SHBs with higher Braak NFT stage, PSP and argyrophilic grain disease and HBLs with MSA.

CONCLUSIONS

This study demonstrates that HBs are associated with diverse neurodegenerative diseases and shows that morphological types appear distinctively in various conditions.

Model Hirano bodies protect against tau-independent and tau-dependent cell death initiated by the amyloid precursor protein intracellular domain

The main pathological hallmarks of Alzheimer's disease are amyloid-beta plaques and neurofibrillary tangles, which are primarily composed of amyloid precursor protein (APP) and tau, respectively. These proteins and their role in the mechanism of neurodegeneration have been extensively studied. Hirano bodies are a frequently occurring pathology in Alzheimer's disease as well as other neurodegenerative diseases. However, the physiological role of Hirano bodies in neurodegenerative diseases has yet to be determined. We have established cell culture models to study the role of Hirano bodies in amyloid precursor protein and tau-induced cell death mechanisms. Exogenous expression of APP and either of its c-terminal fragments c31 or Amyloid Precursor Protein Intracellular Domain c58 (AICDc58) enhance cell death. The presence of tau is not required for this enhanced cell death. However, the addition of a hyperphosphorylated tau mimic 352PHPtau significantly increases cell death in the presence of both APP and c31 or AICDc58 alone. The mechanism of cell death induced by APP and its c-terminal fragments and tau was investigated. Fe65, Tip60, p53, and caspases play a role in tau-independent and tau-dependent cell death. In addition, apoptosis was determined to contribute to cell death. The presence of model Hirano bodies protected against cell death, indicating Hirano bodies may play a protective role in neurodegeneration.

Supratentorial hemangioblastoma: clinical features, prognosis, and predictive value of location for von Hippel-Lindau disease

Supratentorial hemangioblastoma is a rare form of hemangioblastoma; little information is available regarding prognosis, treatment, and clinical characteristics, because the available literature is primarily composed of case reports and small case series. Therefore, we performed a systematic review of the literature to analyze clinical characteristics, disease progression, and surgical outcomes with respect to survival for supratentorial hemangioblastomas. The rate of progression-free survival (PFS) was determined using Kaplan-Meier analysis. Differences in categorical factors, including location of tumor and diagnosis of von Hippel-Lindau (VHL) disease, were analyzed using the Pearson χ(2) test. A total of 106 articles met the search criteria, which combined for a total of 132 patients. Of the patients with supratentorial tumors, 60% had VHL disease, and 31 (84%) of 37 patients with tumors in the sellar/suprasellar region had associated VHL (χ(2), P < .001). Five-year PFS for gross-total resection and subtotal resection were 100% and 53%, respectively (Log rank, P < .01). On the basis of our analysis of the literature on published cases of supratentorial hemangioblastoma, gross-total resection appears to be superior to other treatment modalities in extending PFS. Von Hippel-Lindau disease is positively correlated with supratentorial hemangioblastoma when compared with non-supratentorial CNS hemangioblastomas, particularly when present in the sellar/suprasellar region.

Actin and Diseases of the Nervous System

Abnormal regulation of the actin cytoskeleton results in several pathological conditions affecting primarily the nervous system. Those of genetic origin arise during development, but others manifest later in life. Actin regulation is also affected profoundly by environmental factors that can have sustained consequences for the nervous system. Those consequences follow from the fact that the actin cytoskeleton is essential for a multitude of cell biological functions ranging from neuronal migration in cortical development and dendritic spine formation to NMDA receptor activity in learning and alcoholism. Improper regulation of actin, causing aggregation, can contribute to the neurodegeneration of amyloidopathies, such as Down's syndrome and Alzheimer's disease. Much progress has been made in understanding the molecular basis of these diseases.

Formation of Hirano bodies induced by expression of an actin cross-linking protein with a gain-of-function mutation

Hirano bodies are paracrystalline actin filament-containing structures reported to be associated with a variety of neurodegenerative diseases. However, the biological function of Hirano bodies remains poorly understood, since nearly all prior studies of these structures were done with postmortem samples of tissue. In the present study, we generated a full-length form of a Dictyostelium 34-kDa actin cross-linking protein with point mutations in the first putative EF hand, termed 34-kDa DeltaEF1. The 34-kDa DeltaEF1 protein binds calcium normally but has activated actin binding that is unregulated by calcium. The expression of the 34-kDa DeltaEF1 protein in Dictyostelium induces the formation of Hirano bodies, as assessed by both fluorescence microscopy and transmission electron microscopy. Dictyostelium cells bearing Hirano bodies grow normally, indicating that Hirano bodies are not associated with cell death and are not deleterious to cell growth. Moreover, the expression of the 34-kDa DeltaEF1 protein rescues the phenotypes of cells lacking the 34-kDa protein and cells lacking both the 34-kDa protein and alpha-actinin. Finally, the expression of the 34-kDa DeltaEF1 protein also initiates the formation of Hirano bodies in cultured mouse fibroblasts. These results show that the failure to regulate the activity and/or affinity of an actin cross-linking protein can provide a signal for the formation of Hirano bodies. More generally, the formation of Hirano bodies is a cellular response to or a consequence of aberrant function of the actin cytoskeleton.

Formation of Hirano bodies in Dictyostelium and mammalian cells induced by expression of a modified form of an actin-crosslinking protein

We report the serendipitous development of the first cultured cell models of Hirano bodies. Myc-epitope-tagged forms of the 34 kDa actin bundling protein (amino acids 1-295) and the CT fragment (amino acids 124-295) of the 34 kDa protein that exhibits activated actin binding and calcium-insensitive actin filament crosslinking activity were expressed in Dictyosteliumand mammalian cells to assess the behavior of these modified forms in vivo. Dictyostelium cells expressing the CT-myc fragment: (1) form ellipsoidal regions that contain ordered assemblies of F-actin, CT-myc, myosin II, cofilin and α-actinin; (2) grow and develop more slowly than wildtype, but produce normal morphogenetic structures; (3) perform pinocytosis and phagocytosis normally; and (4) produce a level of total actin equivalent to wildtype, but a higher level of F-actin. The paracrystalline inclusions bear a striking resemblance to Hirano bodies, which are associated with a number of pathological conditions. Furthermore, expression of the CT fragment in murine L cells results in F-actin rearrangements characterized by loss of stress fibers, accumulation of numerous punctate foci, and large perinuclear aggregates, the Hirano bodies. Thus, failure to regulate the activity and/or affinity of an actin crosslinking protein can provide a signal for formation of Hirano bodies. More generally, formation of Hirano bodies is a cellular response to or a consequence of aberrant function of the actin cytoskeleton. The results reveal that formation of Hirano bodies is not necessarily related to cell death. These cultured cell models should facilitate studies of the biochemistry, genetics and physiological effects of Hirano bodies.

Hirano bodies and chronic alcoholism

Experiments on rodents have shown convincingly that chronic ethanol ingestion may damage the hippocampal formation. Nevertheless this region has, hitherto, not been considered as a target for alcoholism-induced brain lesions in man. Guided by the observation of increased numbers of Hirano bodies (HB) in the hippocampus of chronic alcoholics, this study determines the maximum number of HB per high power field (HPF: 0.19 mm2) in the stratum pyramidale (HBpyr) and in the stratum lacunosum (HBlac) of Ammon's horn in 123 chronic alcoholics and in 197 controls. The average count of HBlac found in alcoholics was 14.4 (SD = 17.7) compared with 4.2 (SD = 7.4) in non-alcoholics (P < 0.001). Counts of more than 19 HBlac per HPF were revealed as highly indicative of chronic alcoholism being observed in 33 (27%) alcoholics and in six (3%) non-alcoholics (P < 0.001). An increased number of HBlac was the most frequent of the neuropathological findings in the alcoholics. Affirming observations of others, the count of HBlac peaked during middle age and declined thereafter. The maximum count of HBpyr, in contrast, increased with age and was independent of alcoholism. It is proposed that increased numbers of HBlac indicate alterations of the apical dendrites of the pyramidal neurons of the CA1 field of Ammon's horn which probably are due to direct neurotoxic effects of ethanol and which may be reversible in nature.

Ultrastructure of cerebellar capillary hemangioblastoma. VI. Concentric lamellar bodies of endoplasmic reticulum in stromal cells

Concentric lamellar bodies of endoplasmic reticulum (CLB) were found in the stromal cells of all five cases of cerebellar capillary hemangioblastoma studied ultrastructurally. CLB were often present in the stromal cells with voluminous loose cytoplasm, particularly those close to the capillaries. They were rarely seen in small stromal cells with abundant organelles and stromal cells distended by large lipid droplets. Small lipid droplets were usually present in the center or in the vicinity of CLB. Vesiculation and vacuolization of the lamellar arrays of CLB were common. Some vacuolized CLB were transformed into large, varying-shaped, multilocular bodies. Some stromal cells were markedly distended by numerous large vacuoles derived from CLB. Granulo-fibrillary material was frequently present in the vacuolized lamellae. Discharge of vacuoles into the interstitial space was observed. It is suggested that CLB is one of the characteristic ultrastructural features of the stromal cells. They may represent a special type of hyperplasia of the endoplasmic reticulum, but their functional significance is not known.

Hirano body in an inflammatory cell of leptomeningeal vessel infected by fungus Paecilomyces

An intracytoplasmic microfilamentous lattice, ultrastructurally identical to Hirano body, was found in an inflammatory cell within a leptomeningeal vessel wall infected by fungus Paecilomyces javanicus. The structure was well preserved and not associated with phagosomes. This is the first report of Hirano body found in an inflammatory cell at the site of fungal infection. The present finding suggests that the formation of Hirano body is non-specific and not restricted to the cell of the neuro-muscular system.

Hirano body in extraocular muscle

Thirty-three rectus superior extraocular muscles from 23 autopsy cases, all over 60 years, were examined. Eosinophilic inclusions (Hirano bodies) were observed in all the muscles; they were stained deep red by Masson's trichrome stain and were positive for protein stain. They consisted of a collection of filamentous structures of two types: (1) a regular array of filaments 100 A in diameter which sometimes were arrayed in perpendicular planes and (2) another type in a herring bone or ladder-like pattern. Both structures were closely associated with the accumulated thin filaments 50-60 A in diameter (actin?) in the subsarcolemma. The frequent appearance in aged muscle fibers of Hirano bodies indicates that their formation is a change closely related with aging.

A typical presenile dementia. Report of an anatomo-clinical case and review of the literature

A clinico-pathological report is given of a case of dementia of frontal type with EEG changes, associated with a diffuse neuronal loss, subcortical gliosis and laminar spongiosis in the superficial part of the 2nd cortical layer. The authors discuss the cortical biopsy and the post-mortem findings in their case. They draw a comparison between their case an two conditions known as "progressive sub-cortical gliosis" and "Kraepelin's disease" which might be a single entity "atypical presenile dementia".

Crystalloid inclusions reminiscent of Hirano bodies in autolyzed peripheral nerve of normal wistar rats

In a study of experimental autolysis of peripheral nerves of normal Wistar rats, crystalloid inclusions similar to Hirano bodies were observed. They occurred in the nuclei and cytoplasms of Schwann cells and in myelinated axons. They first developed after a 12-h autolysis and increased in number and size with time. Their fine structure, localization, and morphogenesis are discussed in relation to the autolysis of the cellular organelles.

Morphogenesis of the Hirano body in neurons of the squirrel monkey dorsal horn

Electron microscopic investigation of laminae I-III in the lumbosacral region of the squirrel monkey spinal cord has disclosed possible stages in the morphogenesis of the Hirano body. These bodies occur occasionally in nerve cell bodies and dendrites. They are round to oval in shape, measure up to 2.2 micrometer in diameter and are composed of circular layers of 10 nm filaments. In several instances in the present study, Hirano bodies were observed in close association with the Golgi apparatus. Here Golgi-related vesicles were attached to the external surface of the Hirano bodies. In one instance a cluster of developing Hirano bodies of various sizes was observed. The smaller bodies were located nearest the Golgi apparatus while the larger were further away. In this case several short filaments, which may be precursors of the longer filaments which make up the layers of the inclusion, were observed in the cytoplasm between the Golgi cisternae and the smaller Hirano bodies. These observations suggest that the Golgi apparatus plays a major role in the production of the Hirano body. The significance of the occurrence of these inclusions is discussed.

Rod-shaped filamentous inclusions and other ultrastructural features in a cerebellar astrocytoma

A biopsy specimen of a cerebellar astrocytoma from a 14-year-old girl was studied by light and electron microscopy. Histologically the tumor showed a mixture of loose and compact areas with numerous Rosenthal fibers. By electron microscopy most tumor cells contained, besides the usual organelles, large amounts of 70 to 100 A thick filaments. Classical Rosenthal fibers were also identified. In addition many cell bodies and processes were sprinkled with fragments of Rosenthal fiber material. Ordered filamentous arrays (so-called Hirano bodies) were seen in a number of tumor astrocytes. They are considered to be a nonspecific arrangement of filament units largely devoid of cytopathologic significance. Other ultrastructural features of some tumor cells were inchoate forms of the granulated bodies of conventional histology, paired cisternal elements of rough endoplasmic reticulum, and honeycomb-like profiles of transversely cut cylindrical units of smooth endoplasmic reticulum. Microtubular bodies were numerous in the endothelial cells of the tumor vessels.