Glucocerebrosidase gene (GBA) variants that cause Gaucher disease are associated with Parkinson disease (PD) and dementia with Lewy bodies (DLB). To investigate the role of GBA variants in multiple system atrophy (MSA), we analyzed GBA variants in a large case-control series.

Amyotrophic lateral sclerosis (ALS) is a devastating neurological disorder characterized by the degeneration of motor neurons and typically results in death within 3-5 years from onset. Familial ALS (FALS) comprises 5%-10% of ALS cases, and the identification of genes associated with FALS is indispensable to elucidating the molecular pathogenesis. We identified a Japanese family affected by late-onset, autosomal-dominant ALS in which mutations in genes known to be associated with FALS were excluded. A whole- genome sequencing and parametric linkage analysis under the assumption of an autosomal-dominant mode of inheritance with incomplete penetrance revealed the mutation c.2780G>A (p. Arg927Gln) in ERBB4. An extensive mutational analysis revealed the same mutation in a Canadian individual with familial ALS and a de novo mutation, c.3823C>T (p. Arg1275Trp), in a Japanese simplex case. These amino acid substitutions involve amino acids highly conserved among species, are predicted as probably damaging, and are located within a tyrosine kinase domain (p. Arg927Gln) or a C-terminal domain (p. Arg1275Trp), both of which mediate essential functions of ErbB4 as a receptor tyrosine kinase. Functional analysis revealed that these mutations led to a reduced autophosphorylation of ErbB4 upon neuregulin-1 (NRG-1) stimulation. Clinical presentations of the individuals with mutations were characterized by the involvement of both upper and lower motor neurons, a lack of obvious cognitive dysfunction, and relatively slow progression. This study indicates that disruption of the neuregulin-ErbB4 pathway is involved in the pathogenesis of ALS and potentially paves the way for the development of innovative therapeutic strategies such using NRGs or their agonists to upregulate ErbB4 functions.

Frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS) are types of major TDP-43 (43-kDa TAR DNA-binding protein) proteinopathy. Cortical TDP-43 pathology has been analyzed in detail in cases of FTLD-TDP, but is still unclear in cases of ALS. We attempted to clarify the cortical and subcortical TDP-43 pathology in Japanese cases of sporadic ALS (n = 96) using an antibody specific to phosphorylated TDP-43 (pTDP-43). The cases were divided into two groups: those without pTDP-43-positive neuronal cytoplasmic inclusions in the hippocampal dentate granule cells (Type 1, n = 63), and those with such inclusions (Type 2, n = 33). Furthermore, the Type 2 cases were divided into two subgroups based on semi-quantitative estimation of pTDP-43-positive dystrophic neurites (DNs) in the temporal neocortex: Type 2a (accompanied by no or few DNs, n = 22) and Type 2b (accompanied by abundant DNs, n = 11). Clinico-pathologic analysis revealed that cognitive impairment was a feature in patients with Type 2a and Type 2b, but not in those with Type 1, and that importantly, Type 2b is a distinct subtype characterized by a poor prognosis despite the less severe loss of lower motor neurons, the unusual subcortical dendrospinal pTDP-43 pathology, and more prominent glial involvement in cortical pTDP-43 pathology than other two groups. Considering the patient survival time and severity of motor neuron loss in each group, transition from Type 1 to Type 2, or from Type 2a to Type 2b during the disease course appeared unlikely. Therefore, each of these three groups was regarded as an independent subtype.

Amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disease caused by selective loss of motor neurons. In the ALS motor neurons, TAR DNA-binding protein of 43 kDa (TDP-43) is dislocated from the nucleus to cytoplasm and forms inclusions, suggesting that loss of a nuclear function of TDP-43 may underlie the pathogenesis of ALS. TDP-43 functions in RNA metabolism include regulation of transcription, mRNA stability, and alternative splicing of pre-mRNA. However, a function of TDP-43 in tissue affected with ALS has not been elucidated. We sought to identify the molecular indicators reflecting on a TDP-43 function. Using exon array analysis, we observed a remarkable alteration of splicing in the polymerase delta interacting protein 3 (POLDIP3) as a result of the depletion of TDP-43 expression in two types of cultured cells. In the cells treated with TDP-43 siRNA, wild-type POLDIP3 (variant-1) decreased and POLDIP3 lacking exon 3 (variant-2) increased. The RNA binding ability of TDP-43 was necessary for inclusion of POLDIP3 exon 3. Moreover, we found an increment of POLDIP3 variant-2 mRNA in motor cortex, spinal cord and spinal motor neurons collected by laser capture microdissection with ALS. Our results suggest a loss of TDP-43 function in tissues affected with ALS, supporting the hypothesis that a loss of function of TDP-43 underlies the pathogenesis of ALS.

Clinical characteristics of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) include migraine, recurrent stroke, white matter lesions, and vascular dementia. CADASIL is one of the most common hereditary cerebral small vessel diseases. Clinical presentation of CADASIL varies and a racial gap may exist between the Asian and Caucasian populations. This is the first nationwide epidemiological survey which aimed to elucidate the clinical features of CADASIL in Japan. Moreover, the registration database of CADASIL was constructed.

Multiple system atrophy (MSA) is an adult-onset neurodegenerative disorder that has both clinical and pathological variants. Clinical examples include MSA with predominant cerebellar ataxia (MSA-C) and MSA with predominant parkinsonism (MSA-P), whereas olivopontocerebellar atrophy and striatonigral degeneration represent pathological variants. We performed systematic reviews of studies that addressed the relative frequencies of clinical or pathological variants of MSA in various populations to determine the clinicopathological characteristics in Japanese MSA. The results revealed that the majority of Japanese patients have MSA-C, while the majority of patients in Europe and North America have MSA-P. A comparative study of MSA pathology showed that the olivopontocerebellar-predominant pathology was more frequent in Japanese MSA than in British MSA. Demonstrated differences in pathological subtype thus appear consistent with differences in the clinical subtype of MSA demonstrated between Japan and European populations. We concluded that olivopontocerebellar-predominant pathology and MSA-C may represent clinicopathological characteristics in Japanese MSA. Factors determining predominant involvement of olivopontocerebellar regions in MSA should therefore be explored.

Definite diagnosis of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukocencephalopathy (CADASIL) is mostly done by identification of NOTCH3 mutations. We aimed to develop criteria for selecting patients suspected for CADASIL to undergo genetic testing.

No abstract available

It is increasingly becoming apparent that cerebrovascular dysfunction contributes to the pathogenic processes involved in vascular dementia, Alzheimer's disease, and other neurodegenerative disorders. Under these pathologic conditions, the degeneration of cerebral blood vessels is frequently accompanied by a loss of mural cells from the vascular walls. Vascular mural cells play pivotal roles in cerebrovascular functions, such as regulation of cerebral blood flow and maintenance of the blood-brain barrier (BBB). Therefore, cerebrovascular mural cell impairment is involved in the pathophysiology of vascular-related encephalopathies, and protecting these cells is essential for maintaining brain health. However, our understanding of the molecular mechanism underlying mural cell abnormalities is incomplete. Several reports have indicated that dysregulated transforming growth factor β (TGFβ) signaling is involved in the development of cerebral arteriopathies. These studies have specifically suggested the involvement of TGFβ overproduction. Although cerebrovascular toxicity via vascular fibrosis by extracellular matrix accumulation or amyloid deposition is known to occur with enhanced TGFβ production, whether increased TGFβ results in the degeneration of vascular mural cells in vivo remains unknown. Here, we demonstrated that chronic TGFβ1 overproduction causes a dropout of mural cells and reduces their coverage on cerebral vessels in both smooth muscle cells and pericytes. Mural cell degeneration was also accompanied by vascular luminal dilation. TGFβ1 overproduction in astrocytes significantly increased TGFβ1 content in the cerebrospinal fluid (CSF) and increased TGFβ signaling-regulated gene expression in both pial arteries and brain capillaries. These results indicate that TGFβ is an important effector that mediates mural cell abnormalities under pathological conditions related to cerebral arteriopathies.

Mitochondrial dysfunction and lysosomal dysfunction have been implicated in Parkinson's disease (PD), but the links between these dysfunctions in PD pathogenesis are still largely unknown. Here we report that cytosolic dsDNA of mitochondrial origin escaping from lysosomal degradation was shown to induce cytotoxicity in cultured cells and PD phenotypes in vivo. The depletion of PINK1, GBA and/or ATP13A2 causes increases in cytosolic dsDNA of mitochondrial origin and induces type I interferon (IFN) responses and cell death in cultured cell lines. These phenotypes are rescued by the overexpression of DNase II, a lysosomal DNase that degrades discarded mitochondrial DNA, or the depletion of IFI16, which acts as a sensor for cytosolic dsDNA of mitochondrial origin. Reducing the abundance of cytosolic dsDNA by overexpressing human DNase II ameliorates movement disorders and dopaminergic cell loss in gba mutant PD model zebrafish. Furthermore, IFI16 and cytosolic dsDNA puncta of mitochondrial origin accumulate in the brain of patients with PD. These results support a common causative role for the cytosolic leakage of mitochondrial DNA in PD pathogenesis.

Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) is an inherited cerebral small vessel disease (CSVD) caused by biallelic mutations in the high-temperature requirement serine peptidase A1 (HTRA1) gene. Even heterozygous mutations in HTRA1 are recently revealed to cause cardinal clinical features of CSVD. Here, we report the first establishment of a human induced pluripotent stem cell (hiPSC) line from a patient with heterozygous HTRA1-related CSVD. Peripheral blood mononuclear cells (PBMCs) were reprogrammed by the transfection of episomal vectors encoding human OCT3/4 (POU5F1), SOX2, KLF4, L-MYC, LIN28, and a murine dominant-negative mutant of p53 (mp53DD). The established iPSCs had normal morphology as human pluripotent stem cells and normal karyotype (46XX). Moreover, we found that the HTRA1 missense mutation (c.905G>A, p.R302Q) was heterozygous. These iPSCs expressed pluripotency-related markers and had the potential to differentiate into all three germ layers in vitro. HTRA1 and the supposed disease-associated gene NOG were differentially expressed in the patient iPSCs at mRNA levels compared to those of control lines. The iPSC line would facilitate in vitro research for understanding the cellular pathomechanisms caused by the HTRA1 mutation including its dominant-negative effect.

No abstract available

Abnormal expansions of GGGGCC repeat sequence in the noncoding region of the C9orf72 gene is the most common cause of familial amyotrophic lateral sclerosis and frontotemporal dementia (C9-ALS/FTD). The expanded repeat sequence is translated into dipeptide repeat proteins (DPRs) by noncanonical repeat-associated non-AUG (RAN) translation. Since DPRs play central roles in the pathogenesis of C9-ALS/FTD, we here investigate the regulatory mechanisms of RAN translation, focusing on the effects of RNA-binding proteins (RBPs) targeting GGGGCC repeat RNAs. Using C9-ALS/FTD model flies, we demonstrated that the ALS/FTD-linked RBP FUS suppresses RAN translation and neurodegeneration in an RNA-binding activity-dependent manner. Moreover, we found that FUS directly binds to and modulates the G-quadruplex structure of GGGGCC repeat RNA as an RNA chaperone, resulting in the suppression of RAN translation in vitro. These results reveal a previously unrecognized regulatory mechanism of RAN translation by G-quadruplex-targeting RBPs, providing therapeutic insights for C9-ALS/FTD and other repeat expansion diseases.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by accumulation of fragmented insoluble TDP-43 and loss of TDP-43 from the nucleus. Increased expression of exogenous TARDBP (encoding TDP-43) induces TDP-43 pathology and cytotoxicity, suggesting the involvement of aberrant expression of TDP-43 in the pathogenesis of ALS. In normal conditions, however, the amount of TDP-43 is tightly regulated by the autoregulatory mechanism involving alternative splicing of TARDBP mRNA. To investigate the influence of autoregulation dysfunction, we inhibited the splicing of cryptic intron 6 using antisense oligonucleotides in vivo. This inhibition doubled the Tardbp mRNA expression, increased the fragmented insoluble TDP-43, and reduced the number of motor neurons in the mouse spinal cord. In human induced pluripotent stem cell-derived neurons, the splicing inhibition of intron 6 increased TARDBP mRNA and decreased nuclear TDP-43. These non-genetically modified models exhibiting rise in the TARDBP mRNA levels suggest that TDP-43 autoregulation turbulence might be linked to the pathogenesis of ALS.

Amyotrophic lateral sclerosis (ALS) is characterized pathologically by the occurrence of phosphorylated TDP-43 (pTDP-43)-immunoreactive neuronal and glial inclusions in the central nervous system. Recent studies have shown that pTDP-43 aggregates also occur in the skeletal muscles in a certain proportion of ALS patients.

A 64-year-old Japanese man with recurrent cerebral ischemic events and cognitive impairment was suspected of having cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) because of a family history and brain magnetic resonance imaging findings of cerebral white matter hyperintensities. The cysteine-sparing variation p.Val237Met was identified in NOTCH3. An intensive skin biopsy showed negative results (no granular osmiophilic material or positive NOTCH3 immunostaining), suggesting that the patient's definite diagnosis and pathogenicity of p.Val237Met were uncertain. We additionally reviewed previous reports of two Japanese families with p.Val237Met.

No abstract available

Although cerebral aneurysm (CA) is a defining complication of COL4A1/2-related vasculopathy, the specific factors influencing its onset remain uncertain. This study aimed to identify and analyze these factors.

Hereditary short stature syndromes are clinically and genetically heterogeneous disorders and the cause have not been fully identified. Yakuts are a population isolated in Asia; they live in the far east of the Russian Federation and have a high prevalence of hereditary short stature syndrome including 3-M syndrome. A novel short stature syndrome in Yakuts is reported here, which is characterised by autosomal recessive inheritance, severe postnatal growth retardation, facial dysmorphism with senile face, small hands and feet, normal intelligence, Pelger-Huët anomaly of leucocytes, and optic atrophy with loss of visual acuity and colour vision. This new syndrome is designated as short stature with optic atrophy and Pelger-Huët anomaly (SOPH) syndrome.

To clarify the genetic, clinicopathologic, and neuroimaging characteristics of patients with hereditary diffuse leukoencephalopathy with spheroids (HDLS) with the colony stimulating factor 1 receptor (CSF-1R) mutation.