Kiyomitsu Oyanagi

Neuropathology with clinical correlations of sporadic amyotrophic lateral sclerosis: 102 autopsy cases examined between 1962 and 2000.

Sporadic amyotrophic lateral sclerosis (ALS) is a fatal neurological disorder affecting adults. We studied the neuropathology and clinical correlations in 102 autopsy cases of ALS. The age at onset of the disease was significantly higher for the bulbar‐onset form (30 cases) than for the limb‐onset form (72 cases). Dementia was confirmed in 7 cases. These 102 cases were divided into 4 pathological subgroups: typical ALS (59 cases), lower‐motor‐predominant ALS (23 cases), ALS with temporal lesions (18 cases), and ALS with pallido‐nigro‐luysian degeneration (2 cases). The age at onset was significantly higher for lower‐motor‐predominant ALS and ALS with temporal lesions than for typical ALS. In the lower motor neurons, Bunina bodies were detected in 88 cases, whereas ubiquitin‐immunoreactive skein and/or spherical inclusions were detected in all 102 cases. Of the 100 available cases, 50 and 16 also showed ubiquitin‐immunoreactive inclusions in the neostriatal and temporal small neurons, respectively. Ubiquitin‐immunoreactive dystrophic neurites were also observed in the neostriatum in 3 of the 50 cases with neostriatal inclusions, and in the temporal cortex in 4 of the 16 cases with temporal inclusions. There was a significant association between the bulbar‐onset form, temporal lesions, neostriatal inclusions and temporal inclusions, and between dementia, temporal lesions and temporal inclusions. Neostriatal and temporal dystrophic neurites were associated with dementia and bulbar‐onset form through temporal lesions and temporal inclusions. The present findings may be helpful for designing further studies on the mechanisms underlying the development of ALS.

Corticobasal degeneration : etiopathological significance of the cytoskeletal alterations

We have studied brain tissues from three patients with corticobasal degeneration (CBD) histologically, ultrastructurally and immunohistochemically. Ballooned neurons in the cerebral cortex and severe degeneration of the substantia nigra were observed in them all and weakly basophilic neurofibrillary tangles (NFTs) were distributed widely in the basal ganglia and brain stem. Ultrastructural examination demonstrated that the NFTs comprised characteristic 15-nm-wide straight tubules, which showed positive immunohistochemical staining with an antibody against tau, but not ubiquitin. Tau-immunoreactive neuronal cell bodies without NFTs also were found in the cerebral cortex and subcortical nuclei, predominantly in the brain stem, and the greatest number of tau-positive glial inclusions occurred in the cerebral gray and white matter of the pre- and post-central gyri. These inclusions comprised tubular structures with diameters of about 15 nm and were localized in the oligodendroglial cellular cytoplasm and processes. These findings indicate that there is a close cytoskeletal pathological relationship between CBD and progressive supranuclear palsy.

Rescue of lesioned adult rat spinal motoneurons by adenoviral gene transfer of glial cell line-derived neurotrophic factor

Glial cell line‐derived neurotrophic factor (GDNF) has been shown to protect cranial and spinal motoneurons, that suggests potential uses of GDNF in the treatment of spinal cord injury and motor neuron diseases. We examined neuroprotective effect of human GDNF encoded by an adenovirus vector (AxCAhGDNF) on the death of lesioned adult rat spinal motoneurons. The seventh cervical segment (C7) ventral and dorsal roots and dorsal root ganglia of adult Fisher 344 rats were avulsed, and AxCAhGDNF, AxCALacZ (adenovirus encoding β‐galactosidase gene) or PBS was inoculated in C7 vertebral foramen. One week after the avulsion and treatment with AxCALacZ, the animals showed expression of β‐galactosidase activity in lesioned spinal motoneurons. Animals avulsed and treated with AxCAhGDNF showed intense immunolabeling for GDNF in lesioned spinal motoneurons and expression of virus‐induced human GDNF mRNA transcripts in the lesioned spinal cord tissue. Nissl‐stained cell counts revealed that the treatment with AxCAhGDNF significantly prevented the loss of lesioned ventral horn motoneurons 2 to 8 weeks after avulsion, as compared to AxCALacZ or PBS treatment. Furthermore, the AxCAhGDNF treatment ameliorated choline acetyltransferase immunoreactivity in the lesioned motoneurons after avulsion. These results indicate that the adenovirus‐mediated gene transfer of GDNF may prevent the degeneration of motoneurons in adult humans with spinal cord injury and motor neuron diseases. J. Neurosci. Res. 60:511–519, 2000

Adenoviral gene transfer of GDNF, BDNF and TGFβ2, but not CNTF, cardiotrophin-1 or IGF1, protects injured adult motoneurons after facial nerve avulsion

We examined neuroprotective effects of recombinant adenoviral vectors encoding glial cell line‐derived neurotrophic factor (GDNF), brain‐derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF), cardiotrophin‐1 (CT1), insulin‐like growth factor‐1 (IGF1), and transforming growth factor‐β2 (TGFβ2) on lesioned adult rat facial motoneurons. The right facial nerves of adult Fischer 344 male rats were avulsed and removed from the stylomastoid foramen, and adenoviral vectors were injected into the facial canal. Animals avulsed and treated with adenovirus encoding GDNF, BDNF, CNTF, CT1, IGF1 and TGFβ2 showed intense immunolabeling for these factors in lesioned facial motoneurons, respectively, indicating adenoviral induction of the neurotrophic factors in these neurons. The treatment with adenovirus encoding GDNF, BDNF, or TGFβ2 after avulsion significantly prevented the loss of lesioned facial motoneurons, improved choline acetyltransferase immunoreactivity and prevented the induction of nitric oxide synthase activity in these neurons. The treatment with adenovirus encoding CNTF, CT1 or IGF1, however, failed to protect these neurons after avulsion. These results indicate that the gene transfer of GDNF and BDNF and TGFβ2 but not CNTF, CT1 or IGF1 may prevent the degeneration of motoneurons in adult humans with motoneuron injury and motor neuron diseases.

Decreased expression of hypothalamic neuropeptides in huntington disease transgenic mice with expanded polyglutamine-EGFP fluorescent aggregates

Huntington disease is caused by polyglutamine (polyQ) expansion in huntingtin. Selective and progressive neuronal loss is observed in the striatum and cerebral cortex in Huntington disease. We have addressed whether expanded polyQ aggregates appear in regions of the brain apart from the striatum and cortex and whether there is a correlation between expanded polyQ aggregate formation and dysregulated transcription. We generated transgenic mouse lines expressing mutant truncated N‐terminal huntingtin (expanded polyQ) fused with enhanced green fluorescent protein (EGFP) and carried out a high‐density oligonucleotide array analysis using mRNA extracted from the cerebrum, followed by TaqMan RT‐PCR and in situ hybridization. The transgenic mice formed expanded polyQ‐EGFP fluorescent aggregates and this system allowed us to directly visualize expanded polyQ aggregates in various regions of the brain without performing immunohistochemical studies. We show here that polyQ‐EGFP aggregates were intense in the hypothalamus, where the expression of six hypothalamic neuropeptide mRNAs, such as oxytocin, vasopressin and cocaine‐amphetamine‐regulated transcript, was down‐regulated in the transgenic mouse brain without observing a significant loss of hypothalamic neurons. These results indicate that the hypothalamus is susceptible to aggregate formation in these mice and this may result in the down‐regulation of specific genes in this region of the brain.

Amyotrophic lateral sclerosis of Guam: the nature of the neuropathological findings

To elucidate the fundamental differences and similarities of the neuropathological features and etiopathogenesis of the amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia complex (PDC) of Guam, we conducted a topographic, quantitative and histological investigation of tau-containing neurons, neurofibrillary tangles (NFTs), Bunina bodies and ubiquitinated inclusion bodies in 27 non-ALS non-PDC Guamanian subjects, as well as 10 Guam ALS patients, 28 PDC patients, and 5 patients with combined ALS and PDC (ALS-PDC). The topographic distribution of NFTs was basically the same in each disease and also in the non-ALS non-PDC group. There were relatively few, if any, NFTs in non-ALS non-PDC subjects and ALS patients, but there were many, especially in the frontal and temporal cortex, in Guam PDC and ALS-PDC patients. The histological and ultrastructural features of Bunina bodies in Guam ALS and ALS-PDC patients were similar to those reported in classic ALS. The ratio of occurrence of the inclusion in Guam ALS and ALS-PDC patients was similar to that reported so far in classic ALS. Ubiquitinated skein-like inclusion bodies were observed in the spinal anterior horn cells in Guam ALS and ALS-PDC patients. These findings indicate that classic ALS does exist on Guam, that NFTs in Guam ALS patients are merely a background feature widely dispersed in the population, that the mechanism of neuronal degeneration of Guam ALS is basically different from that of PDC, and that Guam ALS occurs initially as classic ALS.

Endothelin-1 in the brain of patients with galactosialidosis: its abnormal increase and distribution pattern.

Endothelin‐1 is a peptidic substrate in vitro of lysosomal protective protein/cathepsin A (PPCA) with serine carboxypeptidase activity. Endothelin‐1–specific immunoreactivity has been demonstrated to be markedly increased and distributed abnormally in the neurons and glial cells within autopsied brain regions, including the cerebellum, hippocampal formation, and spinal cord, of patients affected with galactosialidosis, a human PPCA deficiency. The genetic defect of the endothelin‐1 degrading activity of PPCA is suggested to cause some of the neurological abnormalities of this disease. Ann Neurol 2000; 47:122–126

Histone deacetylase activity is retained in primary neurons expressing mutant huntingtin protein.

Perturbation of histone acetyl‐transferase (HAT) activity is implicated in the pathology of polyglutamine diseases, and suppression of the counteracting histone deacetylase (HDAC) proteins has been proposed as a therapeutic candidate for these intractable disorders. Meanwhile, it is not known whether mutant polyglutamine disease protein affects the HDAC activity in declining neurons, though the answer is essential for application of anti‐HDAC drugs for polyglutamine diseases. Here, we show the effect of mutant huntingtin (htt) protein on the expression and activity of HDAC proteins in rat primary cortical neurons as well as in human Huntingtons disease (HD) brains. Our findings indicate that expression and activity of HDAC proteins are not repressed by mutant htt protein. Furthermore, expression of normal and mutant htt protein slightly increased HDAC activity although the effects of normal and mutant htt were not remarkably different. In human HD cerebral cortex, HDAC5 immunoreactivity was increased in the nucleus of striatal and cortical neurons, suggesting accelerated nuclear import of this class II HDAC. Meanwhile, western blot and immunohistochemical analyses showed no remarkable change in the expression of class I HDAC proteins such as HDAC1 and HDCA8. Collectively, retained activity in affected neurons supports application of anti‐HDAC drugs to the therapy of HD.

The intermediolateral nucleus in sporadic amyotrophic lateral sclerosis

SummaryHistological and morphometrical observations of the intermediolateral nucleus (IML) at the levels of the upper and lower thoracic segments (T2 and T9) were carried out in 18 patients with sporadic amyotrophic lateral sclerosis (ALS) and 15 age-matched control subjects. Of the 18 ALS patients 6 had been on a respirator before death. No Bunina bodies were found in the IML neurons in either the ALS patients or the control subjects. Only a small number of spheroids were encountered rarely in the IML in both the patients and controls. The number of neurons in the IML in the non-respirator-supported ALS patients were reduced at T2, but well preserved at T9 compared with the control subjects. In the respirator-supported ALS patients, there was a marked reduction of IML neurons at both T2 and T9. Considering the absence of direct synaptic contacts with anterior horn cells, these neurons, without the formation of Bunina bodies, appeared to be involved primarily in the disease process in sporadic ALS.

Temporary focal cerebral ischemia results in swollen astrocytic end-feet that compress microvessels and lead to focal cortical infarction

We examined the mechanisms underlying the abrupt onset of the focal infarction in disseminated selective neuronal necrosis (DSNN) after temporary ischemia. Stroke-positive animals were selected according to their stroke-index score during the first 10 minutes after left carotid occlusion performed twice at a 5-hour interval. The animals were euthanized at various times after the second ischemia. Light- and electron-microscopical studies were performed chronologically on the coronal-cut surface of the cerebral cortex at the chiasmatic level, where focal infarction evolved in the maturing DSNN. We counted the number of neurons, astrocytes, and astrocytic processes (APs); measured the areas of end-feet and astrocytes; and counted the numbers of obstructed microvessels and carbon-black-suspension-perfused microvessels (CBSPm). Between 0.5 and 5 hours after ischemia, DSNN matured, with the numbers of degenerated and dead neurons increasing, and those of APs cut-ends decreasing; whereas the area of the end-feet and the numbers of obstructed microvessels increased and those of CBSPm decreased. At 12 and 24 hours after ischemia, the infarction evolved, with the area of end-feet and astrocytic number decreased; whereas the numbers of obstructed microvessels decreased and the CBSPm number increased. The focal infarction evolved by temporary microvascular obstruction because of compression by swollen end-feet.