Shintaro Hayashi

A case of hereditary diffuse leukoencephalopathy with axonal spheroids caused by a de novo mutation in CSF1R masquerading as primary progressive multiple sclerosis

We report a sporadic case of hereditary diffuse leukoencephalopathy with axonal spheroids (HDLS) confirmed by biopsy and colony-stimulating factor 1 receptor (CSF1R) sequencing. A 28-year-old woman developed progressive spastic gait and dysarthria. Brain T2/FLAIR-weighted magnetic resonance imaging showed bilateral high signal intensity lesions in the parietal deep white matter, which subsequently extended anteriorly. Biopsied brain specimens demonstrated demyelinated white matter tissue with axonal spheroids infiltrated with foamy macrophages, and CD8+ and CD4+ T cells. She had a heterozygous mutation, c.2381T>C (p.782 Ile>Thr), in CSF1R. This is the first genetically proven case of HDLS mimicking primary progressive multiple sclerosis.

Extensive dysregulations of oligodendrocytic and astrocytic connexins are associated with disease progression in an amyotrophic lateral sclerosis mouse model

BackgroundNon-cell-autonomous motor neuronal death is suggested in a mutant Cu/Zn superoxide dismutase 1 (mSOD1)-mediated amyotrophic lateral sclerosis (ALS) model, in which glial cells play significant roles in disease progression. Connexins (Cxs) form homotypic or heterotypic gap junctions (GJs) and allow direct intercellular communications among nervous tissue cells. The role of Cxs in motor neuron disease has never been investigated; therefore, we aimed to evaluate alterations of Cxs in mSOD1-transgenic (mSOD1-Tg) mice in comparison with their non-transgenic (non-Tg) littermates at the same ages.MethodsWe pathologically evaluated temporal changes to astrocytic Cx43/Cx30 and oligodendrocytic Cx47/Cx32 immunoreactivities at presymptomatic, disease-progressive, and end stages, relative to aquaporin-4 (AQP4), glial fibrillary acidic protein (GFAP), excitatory amino acid transporter-2 (EAAT2), myelin-oligodendrocyte glycoprotein (MOG), and Nogo-A immunoreactivities, and observed neuronal loss by NeuN and neurofilament immunostaining, and microglial response by Iba-1 immunostaining. We also performed quantitative immunoblotting and real-time PCR analyses for Cxs.ResultsThe mSOD1-Tg mice showed neuronal and axonal loss in the anterior horns of the lumbar spinal cord accompanied by increased activation of microglia compared with non-Tg mice at the disease-progressive and end stages. Expression patterns of Cxs were not different between mSOD1-Tg and non-Tg mice at the presymptomatic stage, but immunoreactivities for GFAP, Cx43, Cx30 and AQP4 were increased in the anterior horns of mSOD1-Tg mice at the disease-progressive and end stages. By contrast, Cx47 and Cx32 immunoreactivities were markedly diminished in Nogo-A-positive oligodendrocytes in the anterior horns of mSOD1-Tg mice at the disease-progressive and end stages, especially in oligodendrocytes showing SOD1 accumulation. EAAT2 immunoreactivity was also diminished in the anterior horns of mSOD1-Tg mice at the disease-progressive and end stages. Quantitative immunoblotting revealed a significant reduction in Cx47 and Cx32 protein levels in mSOD1-Tg mice at the disease-progressive and end stages. The levels of Cx47 and Cx32 mRNAs were also decreased at these stages.ConclusionsOur findings indicate that oligodendrocytic and astrocytic GJ proteins in the anterior horns of spinal cord in mSOD1-Tg mice are profoundly affected at the disease-progressive and end stages, where disruption of GJs among glial cells may exacerbate motor neuronal death.

Impaired cytoplasmic-nuclear transport of hypoxia-inducible factor-1α in amyotrophic lateral sclerosis

We investigated the mechanisms underlying abnormal vascular endothelial growth factor (VEGF) production in amyotrophic lateral sclerosis (ALS). We immunohistochemically studied VEGF, its receptors VEGFR1 and 2, and hypoxia‐inducible factor‐1α (HIF‐1α) in autopsied ALS spinal cords. We also chronologically assessed the expression of HIF‐1α, karyopherin β1, karyopherin β‐cargo protein complex inhibitors and nuclear pore complex proteins in G93A mutant superoxide dismutase 1 (mSOD1) transgenic mice at presymptomatic, symptomatic and end stages. In ALS patients, compared with controls, HIF‐1α immunoreactivity in the cytoplasm of anterior horn cells (AHCs) was significantly increased, while immunoreactivities for VEGF and VEGFRs were significantly decreased. Similar changes in HIF‐1α and VEGF levels were observed in mSOD1 transgenic mice. HIF‐1α co‐localized with karyopherin β1 in the cytoplasm of AHCs and karyopherin β1 co‐localized with nucleoporin 62 (Nup62) on the nuclear envelope. From the presymptomatic stage of mSOD1 transgenic mice, karyopherin β1 immunoreactivity in AHC nuclei significantly decreased and morphological irregularities of the Nup62‐immunostained nuclear envelope became more pronounced with disease progression. Thus, in AHCs from mSOD1 transgenic mice, transport of cytoplasmic HIF‐1α to the nuclear envelope and into the nucleus is impaired from the presymptomatic stage, suggesting that impaired cytoplasmic–nuclear transport of HIF‐1α through the nuclear pore might precede motor neuron degeneration.

Pathological study of the diffuse myelin pallor in the anterolateral columns of the spinal cord in amyotrophic lateral sclerosis

An immunohistochemical study using a monoclonal antibody against macrophage (Ki-M1p) was performed to examine which fiber tracts are affected in the spinal cords and brainstems of ALS patients. In 21 out of 30 ALS patients, various degrees of macrophage infiltration were observed diffusely in the anterolateral columns beyond the corticospinal tracts. On the other hand, a few macrophages were scattered in 20 non-ALS patients in the anterolateral columns outside the corticospinal tracts. In ALS brainstems, the macrophages were mainly localized in the corticospinal tracts. The result suggests that the diffuse myelin pallor in the anterolateral columns beyond the corticospinal tracts may be derived from intrinsic spinal cord lesions. Quantitative investigation using a monoclonal antibody against phosphorylated neurofilaments (SMI-31) revealed that the decrease in the numbers of small fibers would induce the diffuse myelin pallor in anterolateral columns of ALS patients. From these findings, we propose that the propriospinal bundles are candidates for the degenerating fibers in the anterolateral columns of ALS.

Variable expression of microglial DAP12 and TREM2 genes in Nasu-Hakola disease

Nasu-Hakola disease (NHD) is a form of presenile dementia associated with sclerosing leukoencephalopathy and polycystic lipomembranous osteodysplasia. This extremely rare inherited disease is caused by mutations in either DAP12 or TREM2. The present study was designed to assess the relationship between DAP12/TREM2 genotype, mRNA and protein expression levels by both Western blotting and immunohistochemistry, and the tissue distribution and pathomorphological phenotype of the microglia. Molecular genetic testing performed in three NHD cases confirmed that two cases had mutations in DAP12 and that one case carried a mutation in TREM2. Protein levels were analyzed in four cases. Interestingly, significant DAP12 expression was found in numerous microglia in one NHD case with a homozygous DAP12 single-base substitution, and both real-time PCR and Western blotting confirmed the finding. In contrast, levels of both DAP12 and TREM2, respectively, were much lower in the other cases. Immunohistochemistry using established microglial markers revealed consistently mild activation of microglia in the cerebral white matter although there was no or only little expression of DAP12 in three of the NHD cases. The highly different expression of DAP12 represents the first description of such variable expressivity in NHD microglia. It raises important questions regarding the mechanisms underlying dementia and white matter damage in NHD.

TAR DNA-binding protein 43 pathology in a case clinically diagnosed with facial-onset sensory and motor neuronopathy syndrome: an autopsied case report and a review of the literature.

We report an autopsy case of a 48-year-old female clinically diagnosed with facial-onset sensory and motor neuronopathy (FOSMN) syndrome with TAR DNA-binding protein 43 (TDP-43) pathology. She developed paresthesia involving her whole face, right upper extremity and the right side of her upper trunk, followed by dysphagia, dysarthria, muscle atrophy and weakness with fasciculation in both upper extremities. Her symptoms showed a marked cranial and right-sided dominancy. She had anti-sulfoglucuronyl paragloboside (SGPG) IgG and anti-myelin-associated glycoprotein (MAG) IgG, and repeatedly showed limited response to immunotherapies. Her disease was essentially progressive, culminating in death due to respiratory failure three and a half years after onset. The autopsy revealed severe degeneration of the nuclei of the right trigeminal nerve and right facial nerve and widespread TDP-43-positive glial inclusions in the brainstem tegmentum. Neurons in the hypoglossal nerve nuclei were also shrunken and lost, with TDP-43-positive neuronal inclusions. Neuronal loss and gliosis in the anterior horn, predominantly in the cervical cord, were prominent with TDP-43-positive skein-like inclusions. Bilateral ventral roots were obviously atrophic. Spinal tract degeneration was also prominent in the ventral columns, essentially sparing the anterior corticospinal tracts at the cervical cord level. Additionally there was severe myelin pallor in the right spinal trigeminal tract and right fasciculus cuneatus of the cervical cord. The right spinal root ganglion showed numerous Nageottes nodules and focal lymphocytic infiltration. The present case manifested FOSMN syndrome clinically, while the pathological findings suggested a motor neuron disease like TDP-43 proteinopathy and a possible involvement of immune-mediated neuropathy.

Multiple cerebral infarcts with a few vasculitic lesions in the chronic stage of cerebral amyloid angiopathy-related inflammation

We report a 75‐year‐old man with a 3.5‐year history of cerebral amyloid angiopathy (CAA)‐related inflammation. His initial symptom was headache and sensory aphasia appeared 1 month later. Brain MRI revealed features compatible with meningoencephalitis involving the right frontal, parietal and temporooccipital lobes. A brain biopsy sample from the right parietal lobe showed thickening of the leptomeninges, and granulomatous vasculitis with multinucleated giant cells and vascular Aβ deposits. No vascular lesions were evident by cerebral angiography. Serological examination revealed an elevated level of proteinase 3 anti‐neutrophil cytoplasmic autoantibodies (PR3‐ANCA). The patient was treated with corticosteroids, but this was only partially and temporarily effective. Autopsy revealed marked leptomeningeal thickening with inflammatory cell infiltrates and hemosiderin deposits, many superficial predominantly small infarcts at various stages in the cerebral cortex and only a few cerebral active vasculitic lesions. Immunohistochemically, CAA showing widespread Aβ‐positive blood vessels with double‐barrel formations was demonstrated. In conclusion, we consider that, although the association of PR3‐ANCA with the pathogenesis of Aβ‐associated vasculitis remained unclear, the present case represents a rare example of CAA‐related inflammation at the chronic stage.

A case of synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome presenting with hypertrophic pachymeningitis

A 43-year-old woman with a 3-year history of headache, fever, and swelling of the forehead, presented to our hospital. A general examination revealed palmar and plantar pustules. Blood analyses showed an elevated white blood cell count, C-reactive protein level, and erythrocyte sedimentation rate. Brain MRI revealed a partially thickened cranial bone with gadolinium enhancement, and also abnormally enhanced dura mater. Bone scintigraphy showed involvement of the cranial bone and bilateral sternoclavicular joints. Palmar skin biopsy indicated palmoplantar pustulosis. From these results, SAPHO (synovitis, acne, pustulosis, hyperostosis and osteitis) syndrome with associated hypertrophic pachymeningitis was diagnosed. After corticosteroid therapy and tonsillectomy, the clinical symptoms and radiological abnormalities were improved. Clinicians should be aware of SAPHO as a potential unusual cause of hypertrophic pachymeningitis.

A case of neuromyelitis optica harboring both anti-aquaporin-4 antibodies and a pathogenic mitochondrial DNA mutation for Leber's hereditary optic neuropathy.

We report the first case of definite neuromyelitis optica (NMO) with a pathogenic mitochondrial DNA (mtDNA) mutation for Leber’s hereditary optic neuropathy (LHON) (G11778A point mutation). A 36-year-old Japanese woman had experienced recurrent neurological symptoms originating from involvements of the optic nerves and spinal cord. She finally lost her bilateral vision, and spastic paraparesis and sensory disturbances below the T6 level remained despite intensive immunotherapies. Brain and spinal magnetic resonance imaging (MRI) revealed T2-high-intensity lesions in the optic nerves and thoracic spinal cord, but no lesions in the brain. A blood examination revealed positivity for both anti-aquaproin-4 antibodies and an LHON mtDNA mutation.

Decreased CCR2 and CD62L expressions on peripheral blood classical monocytes in amyotrophic lateral sclerosis

Recent evidence has suggested the importance of an aberrantly activated monocyte system in amyotrophic lateral sclerosis (ALS) pathogenesis. However, the roles of each monocyte subset, namely CD14+CD16− classical monocytes, CD14dimCD16+ non‐classical monocytes and CD14+CD16+ intermediate monocytes, in ALS remain unknown. We aimed to clarify the alterations in the monocyte subset proportions and the surface marker expressions on each monocyte subset in ALS.