Mari Yoshida

Phosphorylated and cleaved TDP-43 in ALS, FTLD and other neurodegenerative disorders and in cellular models of TDP-43 proteinopathy.

Transactivation response (TAR) DNA‐binding protein of Mr 43 kDa (TDP‐43) is a major component of the tau‐negative and ubiquitin‐positive inclusions that characterize amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration which is now referred to as FTLD‐TDP. Concurrent TDP‐43 pathology has been reported in a variety of other neurodegenerative disorders such as Alzheimers disease, forming a group of TDP‐43 proteinopathy. Accumulated TDP‐43 is characterized by phosphorylation and fragmentation. There is a close relationship between the pathological subtypes of FTLD‐TDP and the immunoblot pattern of the C‐terminal fragments of phosphorylated TDP‐43. These results suggest that proteolytic processing of accumulated TDP‐43 may play an important role for the pathological process. In cultured cells, transfected C‐terminal fragments of TDP‐43 are more prone to form aggregates than full‐length TDP‐43. Transfecting the C‐terminal fragment of TDP‐43 harboring pathogenic mutations of TDP‐43 gene identified in familial and sporadic ALS cases into cells enhanced the aggregate formation. Furthermore, we found that methylene blue and dimebon inhibit aggregation of TDP‐43 in these cellular models. Understanding the mechanism of phosphorylation and truncation of TDP‐43 and aggregate formation may be crucial for clarifying the pathogenesis of TDP‐43 proteinopathy and for developing useful therapeutics.

RGMa modulates T cell responses and is involved in autoimmune encephalomyelitis

In multiple sclerosis, activated CD4+ T cells initiate an immune response in the brain and spinal cord, resulting in demyelination, degeneration and progressive paralysis. Repulsive guidance molecule-a (RGMa) is an axon guidance molecule that has a role in the visual system and in neural tube closure. Our study shows that RGMa is expressed in bone marrow–derived dendritic cells (BMDCs) and that CD4+ T cells express neogenin, a receptor for RGMa. Binding of RGMa to CD4+ T cells led to activation of the small GTPase Rap1 and increased adhesion of T cells to intracellular adhesion molecule-1 (ICAM-1). Neutralizing antibodies to RGMa attenuated clinical symptoms of mouse myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE) and reduced invasion of inflammatory cells into the CNS. Silencing of RGMa in MOG-pulsed BMDCs reduced their capacity to induce EAE following adoptive transfer to naive C57BL/6 mice. CD4+ T cells isolated from mice treated with an RGMa-specific antibody showed diminished proliferative responses and reduced interferon-γ (IFN-γ), interleukin-2 (IL-2), IL-4 and IL-17 secretion. Incubation of PBMCs from patients with multiple sclerosis with an RGMa-specific antibody reduced proliferative responses and pro-inflammatory cytokine expression. These results demonstrate that an RGMa-specific antibody suppresses T cell responses, and suggest that RGMa could be a promising molecular target for the treatment of multiple sclerosis.

An autopsy case of spinal muscular atrophy type III (Kugelberg‐Welander disease)

We report an autopsy case of a 67‐year‐old man clinicogenetically diagnosed as having spinal muscular atrophy (SMA) type III (Kugelberg‐Welander disease), showing slowly progressive muscle wasting and weakness of the extremities. His brother showed similar manifestations. Autopsy revealed neuronal loss and severe gliosis in the anterior horns of the spinal cord, a marked neurogenic change of skeletal muscles and mild degeneration of cardiomyocytes. Chromatolytic change was seen in the anterior horn, but not in the Clarkes and thalamic nuclei. The anterior spinal roots were atrophic, and there was loss of myelinated fibers with abundant glial bundles. In addition, degeneration was also observed in the posterior column and dentate nucleus. The pathological features were essentially similar to those of SMA I. Chronic change was prominent while acute change was mild in degree, corresponding to a very long clinical course.

An autopsied case of V180I Creutzfeldt-Jakob disease presenting with panencephalopathic-type pathology and a characteristic prion protein type.

A 73‐year‐old Japanese woman showed slowly progressive aphasia, apraxia and dementia. She had no family history of prion disease or dementia. One year later she showed parkinsonism and corticobasal degeneration was initially suspected. On MRI, the left temporal neocortex seemed swollen on T2‐weighted images in the initial stage, and a later high‐signal intensity region was observed in the cerebral cortex in diffusion‐weighted images. The patient developed myoclonus and an akinetic mutism state 15 months and 22 months after onset, respectively. Consecutive electroencephalography revealed no periodic sharp‐wave complexes. Prion protein (PrP) gene analysis revealed a valine to isoleucine point mutation at codon 180, and methionine homozygosity at codon 129. This patients clinical symptoms and disease course were atypical for Creutzfeldt–Jakob disease (CJD), and a stable state with nasal tube‐feeding lasted several years. She died of respiratory failure at the age of 81, 102 months after the onset. Autopsy revealed widespread spongiform degeneration with weak synaptic‐type PrP deposition, confirming the diagnosis of genetic CJD. Neurons in the cerebral cortex were relatively preserved in number and hypertrophic astrocytosis was generally moderate for such long‐term disease, but cerebral white matter showed diffuse severe myelin pallor with tissue rarefaction suggestive of panencephalopatic‐type pathology. The cerebellar cortex was relatively well preserved with observation of mild spongiform change in the molecular layer, moderate neuron loss in the Purkinje neuron layer, and scattered small plaque‐like PrP deposition. Western blot analysis of protease‐resistant PrP showed a characteristic pattern without a diglycoform band. V180I CJD is an interesting form of genetic CJD with regards to the clinicopathologic, molecular and genetic findings.

Glial fibrillary acidic protein mutations in adult‐onset Alexander disease: clinical features observed in 12 Japanese patients

Yoshida T, Sasayama H, Mizuta I, Okamoto Y, Yoshida M, Riku Y, Hayashi Y, Yonezu T, Takata Y, Ohnari K, Okuda S, Aiba I, Nakagawa M. Glial fibrillary acidic protein mutations in adult‐onset Alexander disease: clinical features observed in 12 Japanese patients. 
Acta Neurol Scand: 2011: 124: 104–108.
© 2010 John Wiley & Sons A/S.

FUS immunoreactivity of neuronal and glial intranuclear inclusions in intranuclear inclusion body disease

F. Mori, K. Tanji, T. Kon, S. Odagiri, M. Hattori, Y. Hoshikawa, C. Kono, K. Yasui, S. Yokoi, Y. Hasegawa, M. Yoshida and K. Wakabayashi (2012) Neuropathology and Applied Neurobiology38, 322–328

Clinicopathological characteristics of FTLD-TDP showing corticospinal tract degeneration but lacking lower motor neuron loss

The presence of frontotemporal lobar degeneration with TDP-43-positive inclusions (FTLD-TDP) showing corticospinal tract (CST) degeneration but lacking lower motor neuron (LMN) loss has been reported, and the term primary lateral sclerosis (PLS) is used to distinguish motor neuron disease (MND) of these cases from amyotrophic lateral sclerosis (ALS). To date, however, details of clinicopathological findings of FTLD-MND-PLS type (FTLD-MND-P) have not been reported. We evaluated medical records and histopathological findings of ten cases of FTLD-MND-P, in comparison with those of six FTLD-MND-ALS type (FTLD-MND-A) cases. The mean age at onset and disease duration of FTLD-MND-P cases were 54 and 12 years, respectively. The first symptoms were frontotemporal dementia showing behavioral abnormality and/or personality change in five cases, semantic dementia in three cases, progressive non-fluent aphasia in one case, and auditory hallucination in one case. Upper motor neuron signs were clinically identified in six of the ten cases. There were no LMN signs throughout the clinical course in any case. Histopathologically, there was no obvious LMN loss or Bunina bodies in the hypoglossal nucleus or spinal cord in any case, whereas the CST was involved in all cases. The cerebral cortex of the six cases showed type 1 of TDP-43 histology defined by Cairns et al., whereas three cases showed type 3 histology, and one case showed type 2 histology. In all cases, TDP-43 positive neuronal cytoplasmic inclusions were absent or rare in the LMNs, while TDP-43 positive round structures were frequently identified in the neuropil of the spinal cord anterior horn in some cases. This study clarified that FTLD-MND-P cases have characteristic clinicopathological features distinct from those of FTLD-MND-A.

Clinical diagnosis of Creutzfeldt-Jakob disease : Accuracy based on analysis of autopsy-confirmed cases

A clinical diagnosis of Creutzfeldt-Jakob disease (CJD) can be established readily in typical cases but not in atypical cases. To investigate the accuracy of clinical diagnosis of CJD, such diagnoses were evaluated retrospectively in autopsy cases. Sixty cases were clinically diagnosed as cases of CJD, of which seven were excluded on the basis of pathologic analysis. These seven misdiagnosed patients showed progressive dementia or disturbed consciousness. Myoclonus and periodic sharp-wave complexes (PSWCs) similar to those of CJD were noted in five and four of the seven patients, respectively. Fifty-six cases were pathologically confirmed as cases of CJD, and three of these were not diagnosed clinically as cases of CJD. Myoclonus was noted in 53 of the 56 pathologically confirmed cases, and PSWCs were noted in 49 cases. According to the difficulties that occur in atypical CJD cases lacking typical clinical findings, the importance of pathologic examination was emphasized. Further information from clinicopathologically investigated cases, particularly atypical cases, will aid in the definitive clinical diagnosis of CJD.

Brainstem and spinal cord motor neuron involvement with optineurin inclusions in proximal-dominant hereditary motor and sensory neuropathy

Proximal-dominant hereditary motor and sensory neuropathy (HMSN-P) is characterised by slowly progressive proximal-dominant atrophy and weakness with fasciculations, sensory disturbance and autosomal dominant inheritance.1 HMSN-P has been reported in Okinawa and Kansai, Japan, and the disease locus was mapped to 3q13.1.2 3 The clinical entity of HMSN-P remains controversial. Although this disease was originally described as a new HMSN, it has sometimes been referred to as a part of HMSN type 2 or axonal HMSN. On the other hand, some clinical features of HMSN-P are similar to those of familial amyotrophic lateral sclerosis (ALS).1 Here, we report an autopsy case of HMSN-P that exhibited prominent lower motor neuron (LMN) lesions in the spinal cord and in the brainstem nuclei. Furthermore, we demonstrated optineurin (OPTN)-positive inclusions, which are seen in sporadic and familial ALS,4 in the affected neurons of the present case. The patient is the index case of Kansai-type HMSN-P (IV:25 of pedigree 1).3 A 64-year-old man was admitted to a hospital because of gradually developing muscle atrophy and weakness with fasciculations. When he was 51 years old, he had difficulty in climbing up stairs. Five years after the onset, he needed support when walking. Two years later, he was unable to stand up by himself. In a few years, he became bed-ridden. When he was at 64 years of age, he had dysphagia and started tube-feeding after hospitalisation. Neurological examination on admission showed weakness in the facial, soft palate and sternocleidomastoid muscles and tongue atrophy (figure 1A); proximal-dominant weakness and prominent fasciculations were noted; deep …

An autopsy case of lymphomatosis cerebri showing pathological changes of intravascular large B-cell lymphoma in visceral organs

We describe the case of a 61‐year‐old man presenting with subacute encephalopathy. The clinical manifestations included progressive dementia and pyramidal and extrapyramidal tract signs. Brain CT scan and MRI showed diffuse bilateral white matter changes in the cerebral hemispheres, basal ganglia, thalamus and brainstem. No contrast‐enhanced lesion was observed. Peripheral blood studies, CSF analysis, and brain and muscle biopsies were nonspecific and failed to reveal diagnostic evidence of any specific disease. The patient was diagnosed with and treated for a cerebral demyelinating disorder. Post mortem examination showed diffuse infiltration of lymphoma cells without mass lesions in the extensive cerebral white and gray matter with minimal intravascular patterns, particularly in the perivascular and periventricular spaces. These findings were consistent with lymphomatosis cerebri (LC). In other visceral organs such as the lungs, liver, kidneys and adrenal glands, blood vessels were plugged by numerous neoplastic cells which were morphologically and immunohistochemically similar to those observed in the CNS, consistent with intravascular malignant lymphoma (IVL). To our knowledge, this is the first autopsy report showing the coexistence of LC and IVL. This case suggests a possible link between LC and IVL.