Maya Mimuro

Interleukin-25 expressed by brain capillary endothelial cells maintains blood-brain barrier function in a protein kinase Cepsilon-dependent manner.

Interleukin (IL)-25, a member of the IL-17 family of cytokines, is expressed in the brains of normal mice. However, the cellular source of IL-25 and its function in the brain remain to be elucidated. Here, we show that IL-25 plays an important role in preventing infiltration of the inflammatory cells into the central nervous system. Brain capillary endothelial cells (BCECs) express IL-25. However, it is down-regulated by inflammatory cytokines, including tumor necrosis factor (TNF)-α, IL-17, interferon-γ, IL-1β, and IL-6 in vitro, and is also reduced in active multiple sclerosis (MS) lesions and in the inflamed spinal cord of experimental autoimmune encephalomyelitis, an animal model of MS. Furthermore, IL-25 restores the reduced expression of tight junction proteins, occludin, junction adhesion molecule, and claudin-5, induced by TNF-α in BCECs and consequently repairs TNF-α-induced blood-brain barrier (BBB) permeability. IL-25 induces protein kinase Cϵ (PKCϵ) phosphorylation, and up-regulation of claudin-5 is suppressed by PKCϵ inhibitor peptide in the IL-25-stimulated BCECs. These results suggest that IL-25 is produced by BCECs and protects against inflammatory cytokine-induced excessive BBB collapse through a PKCϵ-dependent pathway. These novel functions of IL-25 in maintaining BBB integrity may help us understand the pathophysiology of inflammatory brain diseases such as MS.

Transition metal abnormalities in progressive dementias.

Abnormal distributions of transition metals inside the brain are potential diagnostic markers for several central nervous system diseases, including Alzheimer’s disease (AD), Parkinson’s disease, dementia with Lewy bodies (DLB), bipolar disorders and depression. To further explore this possibility, the total concentrations of iron, zinc, copper, manganese, aluminum, chromium and cadmium were measured in post-mortem hippocampus and amygdala tissues taken from AD, DLB and Control patients. A statistically significant near fifty percent reduction in the total copper levels of AD patients was observed in both the hippocampus and amygdala. The statistical power of the hippocampus and amygdala copper analysis was found to be 86 and 74% respectively. No statistically significant deviations in the total metal concentrations were found for zinc, manganese, chromium or aluminum. Iron was found to be increased by 38% in AD amygdala tissues, but was unchanged in AD hippocampus tissues. Accounting for differences in tissue water content, as a function of both tissue type and disease state, revealed more consistencies with previous literature. To aid in the design of future experiments, the effect sizes for all tissue types and metals studied are also presented.

Argyrophilic grain disease: frequency and neuropathology in centenarians

Argyrophilic grain disease (AGD) is a progressive degenerative disease of the human brain, the prevalence of which increases with advancing age. The features of AGD in autopsied brains from 32 centenarians were studied using phosphorylated tau (AT8) immunostaining combined with Gallyas–Braak staining and 4R tau-specific antibody (RD4) immunostaining. Ten of 32 centenarians were diagnosed as AGD, yielding an overall frequency of 31.3%. In the demented group, nine (39.1%) of 23 cases were found with argyrophilic grains (AGs), while in the non-demented group, AGs were found in only one (11.1%) of nine cases, the difference between them being significant (P<0.05). Among the cases with Alzheimer’s disease (AD), five (41.7%) of 12 were found with AGs. One (25%) of four cases with senile dementia with tangles (SDT) also suffered from AGD. Dementia caused by “pure” AGD accounted for 13% (3/23) among demented subjects. Our findings indicated that there is a high frequency of AGD in centenarians. In agreement with previous studies, we favor the view that age may be one of the risk factors for AGD.

An autopsied case of progressive supranuclear palsy presenting with cerebellar ataxia and severe cerebellar involvement

A Japanese male patient presented with gait disturbance at the age of 69 years. His principal symptom was cerebellar ataxia for several years. He was initially diagnosed as having olivopontocerebellar atrophy because dysarthria and ataxia gradually developed, and head CT scan showed apparent atrophy of the cerebellum and brainstem and dilatation of the fourth ventricle. Later, he showed vertical gaze palsy, dysphagia, retrocollis, parkinsonism, axial dominant rigidity and grasp reflex, and therefore, the diagnosis was modified to progressive supranuclear palsy (PSP). Progressive atrophy of the frontotemporal lobe, cerebellum and brainstem, and dilatation of the lateral, third and fourth ventricles were evident on MRI. Gastrostomy and tracheotomy were performed 9 and 10 years after onset, respectively, and the patient died after 11 years disease duration. At autopsy the brain weighed 1000 g and showed atrophy of the frontotemporal lobe, cerebellum and brainstem. Neurofibrillary tangles, mainly globose‐type revealed by Gallyas‐Braak silver staining, were extensively observed in the cerebral cortex and subcortical grey matter. Numerous glial fibrillary tangles, including tuft‐shaped astrocytes and coiled bodies, and extensive argyrophilic threads were also recognized, particularly in the frontal lobe, basal ganglia, cerebellar white matter, brainstem and spinal cord. The Purkinje cell layer showed severe neuron loss with Bergmanns gliosis, and the dentate nucleus showed severe neuron loss with grumose degeneration. Tau‐positive/Gallyas‐positive inclusions in the Purkinje cells and the glial cells of the Purkinje cell layer were observed. Pathological findings of the present patient were consistent with the diagnosis of PSP, but the olivopontocerebellar involvement, particularly in the cerebellum, was generally more severe, and the quantity of tau‐positive/Gallyas‐positive structures were more abundant than in typical PSP cases. The existence of a distinct, rare PSP subtype with severe olivopontocerebellar involvement, “PSP‐C“, which tends to be clinically misdiagnosed as spinocerebellar degeneration in the early disease stage, is noteworthy. The present case corresponded to this rare subtype of PSP.

Characteristics of alpha-synucleinopathy in centenarians

To investigate the characteristics of alpha-synucleinopathy in the brains of centenarians, the autopsied brains and spinal cords from 23 cases were studied. Coronal slices were prepared from a section of the cerebral hemisphere, following the guidelines of the Consortium to Establish a Registry for Alzheimer’s Disease (AD) (CERAD) and the consensus guidelines for the clinical and pathologic diagnosis of dementia with Lewy bodies (DLB). Spinal cord specimens were prepared at each segment from the third cervical to the third sacral segment. In all cases, we performed standard stainings of hematoxylin–eosin, Klüver–Barrera, and Gallyas–Braak combined with Luxol fast blue/cresyl violet, and alpha-synuclein (AS), phosphorylated tau (AT8) and beta-amyloid protein immunostainings. One-way ANOVA analysis, Chi-square or Fisher exact test were used for statistical analysis. Overall, AS-positive structures were found in 8 (34.8%) of our 23 centenarians, 6 (35.3%) of 17 demented patients, and four (40%) out of ten AD patients. The frequencies of AS lesions in the brains with senile plaque (SP) stage 0–A, B, and C were 27.7, 33, and 50%, respectively. No statistical differences were found among the frequencies of AS lesions in the subgroups of NFT stages I–II, III–IV, and V–VI (P=0.478). Most cases showed a widespread distribution of AS-positive structures except for one patient, in whose brain only the medulla was involved. The distribution pattern of AS-positive lesions was similar to that in Parkinson’s disease or DLB, but the pigmented neurons in substantia nigra were relatively well preserved. Our findings indicate that there is a high frequency of alpha-synucleinopathy in centenarians, SP-positive and AS-positive lesions may involve a synergistic interaction.

Differential motor neuron involvement in progressive muscular atrophy: a comparative study with amyotrophic lateral sclerosis

Objective Progressive muscular atrophy (PMA) is a clinical diagnosis characterised by progressive lower motor neuron (LMN) symptoms/signs with sporadic adult onset. It is unclear whether PMA is simply a clinical phenotype of amyotrophic lateral sclerosis (ALS) in which upper motor neuron (UMN) signs are undetectable. To elucidate the clinicopathological features of patients with clinically diagnosed PMA, we studied consecutive autopsied cases. Design Retrospective, observational. Setting Autopsied patients. Participants We compared clinicopathological profiles of clinically diagnosed PMA and ALS using 107 consecutive autopsied patients. For clinical analysis, 14 and 103 patients were included in clinical PMA and ALS groups, respectively. For neuropathological evaluation, 13 patients with clinical PMA and 29 patients with clinical ALS were included. Primary outcome measures Clinical features, UMN and LMN degeneration, axonal density in the corticospinal tract (CST) and immunohistochemical profiles. Results Clinically, no significant difference between the prognosis of clinical PMA and ALS groups was shown. Neuropathologically, 84.6% of patients with clinical PMA displayed UMN and LMN degeneration. In the remaining 15.4% of patients with clinical PMA, neuropathological parameters that we defined as UMN degeneration were all negative or in the normal range. In contrast, all patients with clinical ALS displayed a combination of UMN and LMN system degeneration. CST axon densities were diverse in the clinical PMA group, ranging from low values to the normal range, but consistently lower in the clinical ALS group. Immunohistochemically, 85% of patients with clinical PMA displayed 43-kDa TAR DNA-binding protein (TDP-43) pathology, while 15% displayed fused-in-sarcoma (FUS)-positive basophilic inclusion bodies. All of the patients with clinical ALS displayed TDP-43 pathology. Conclusions PMA has three neuropathological background patterns. A combination of UMN and LMN degeneration with TDP-43 pathology, consistent with ALS, is the major pathological profile. The remaining patterns have LMN degeneration with TDP-43 pathology without UMN degeneration, or a combination of UMN and LMN degeneration with FUS-positive basophilic inclusion body disease.

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.

Argyrophilic grains are reliable disease-specific features of corticobasal degeneration.

Argyrophilic grains are discrete punctate structures that bind to silver stains; they can be observed within the neuropil of the limbic system, particularly in the elderly. It has been reported that argyrophilic grains are more frequent in patients with corticobasal degeneration (CBD) compared with the elderly population in general. To determine the frequency and significance of argyrophilic grains in CBD, we examined the temporal lobes from 35 patients with autopsy-proven CBD (mean age, 69.1 years) and 28 patients with argyrophilic grain disease (mean age, 95.7 years). Grain distributions and densities were evaluated semiquantitatively using Gallyas-Braak stains and immunohistochemistry with AT8 and RD4 antibodies. Argyrophilic grains were observed in all CBD cases (100%) despite a lower average age at death in this population. We also observed the following features that were specific to argyrophilic grains in CBD: 1) grains were likely to be widespread throughout the temporal lobe, 2) grains were consistently found with abundant argyrophilic threads, and 3) the ultrastructure of grains contained paired helical filaments with a periodicity of 120 to 130 nm. In conclusion, we confirm that argyrophilic grains in CBD are specifically related to the 4-repeat tau pathology of CBD and are not simply a result of aging.

Clinicopathologic characteristics of five autopsied cases of dura mater-associated Creutzfeldt-Jakob disease

We present five cases of dura mater‐associated Creutzfeldt‐Jakob disease (dura‐CJD) that were analyzed clinicopathologically and review previous reports. The average age at dura mater transplantation was 54.4 ± 7.3 years, and the average age at CJD onset was 66.0 ± 8.2 years, with an average latency period of 11.6 ± 1.1 years. The average age at death was 67.6 ± 8.7 years, with an average CJD disease duration of 16.8 ± 10.4 months. Symptoms of CJD onset in four patients who received dura mater transplantation below the cerebellar tent reflected cerebellar or brainstem dysfunction, whereas symptoms of one patient who received transplantation above the cerebellar tent reflected cerebral cortical involvement. All patients showed rapidly progressive cognitive impairment, and both periodic sharp‐wave complexes on electroencephalogram and myoclonus were observed in the early disease stage. Neuropathologic evaluation showed one case of subacute spongiform encephalopathy and four cases of panencephalopathic‐type CJD. Widespread cerebral neocortical, subcortical gray matter and cerebellar cortical involvement were observed to varying degrees, and severity tended to be associated with CJD disease duration. There were no instances of kuru plaques or florid plaques. Prion protein (PrP) immunostaining showed widespread synaptic‐type PrP deposition. No differences between our dura‐CJD cases and typical cases of sporadic CJD were found with respect to clinicopathologic findings, except history of dura mater transplantation. Although a specific association between the dura mater graft site and neuropathologic observations was not evaluated in the present study, the initial symptoms appear to be closely related to the graft site, indicating a direct transmission of CJD from the graft site to the adjacent brain.

Lower motor neuron involvement in TAR DNA-binding protein of 43 kDa-related frontotemporal lobar degeneration and amyotrophic lateral sclerosis

IMPORTANCE TAR DNA-binding protein of 43 kDa (TDP-43) plays a major role in the pathogenesis of frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). Although a pathological continuity between FTLD and ALS has been suggested, the neuropathological changes of the lower motor neuron (LMN) systems have not been assessed in TDP-43-associated FTLD (FTLD-TDP), to our knowledge. OBJECTIVE To investigate a pathological continuity between FTLD-TDP and ALS by comparing their respective neuropathological changes in the motor neuron system. DESIGN AND SETTING A retrospective clinical medical record review and a semiquantitative neuropathological evaluation of the cranial motor nerve nuclei and spinal cord were conducted at autopsy. We included 43 patients with sporadic FTLD-TDP, type A, B, or C, from 269 consecutively autopsied patients with TDP-43 proteinopathy. Patients were categorized as having FTLD without ALS, FTLD-ALS (onset of FTLD symptoms/signs preceded those of ALS), or ALS-FTLD (onset of ALS symptoms/signs preceded those of FTLD). MAIN OUTCOMES AND MEASURES Neuronal TDP-43 pathological changes and neuronal loss. RESULTS Forty-three patients were included in the clinical analysis, and 29 from whom spinal cords were obtained were included in the neuropathological analysis. Survival time was significantly shorter in the FTLD-ALS and ALS-FTLD groups than in the FTLD without ALS group (P < .001). At neuropathological examination, 89% of patients in the FTLD without ALS group showed aggregations of TDP-43 in the spinal motor neurons. The LMN loss was most severe in ALS-FTLD, followed by FTLD-ALS and FTLD without ALS. All the patients with type A or C FTLD-TDP were included in the FTLD without ALS group, and all those with type B pathological changes were in the FTLD-ALS or the ALS-FTLD group. Lower motor neuron loss and TDP-43-positive skeinlike inclusions were observed in all pathological subtypes. CONCLUSIONS AND RELEVANCE The LMN systems of FTLD-TDP frequently exhibit neuropathological changes corresponding to ALS. Thus, a pathological continuity between FTLD-TDP and ALS is supported at the level of the LMN system.