Novel method for classification of prion diseases by detecting PrPres signal patterns from formalin-fixed paraffin-embedded samples

Prion disease is an infectious and fatal neurodegenerative disease. Western blotting (WB)-based identification of proteinase K (PK)-resistant prion protein (PrPres) is considered a definitive diagnosis of prion diseases. In this study, we aimed to detect PrPres using formalin-fixed paraffin-embedded (FFPE) specimens from cases of sporadic Creutzfeldt-Jakob disease (sCJD), Gerstmann-Sträussler-Scheinker disease (GSS), glycosylphosphatidylinositol-anchorless prion disease (GPIALP), and V180I CJD. FFPE samples were prepared after formic acid treatment to inactivate infectivity. After deparaffinization, PK digestion was performed, and the protein was extracted. In sCJD, a pronounced PrPres signal was observed, with antibodies specific for type 1 and type 2 PrPres exhibited a strong or weak signals depending on the case. Histological examination of serial sections revealed that the histological changes were compatible with the biochemical characteristics. In GSS and GPIALP, prion protein core-specific antibodies presented as PrPres bands at 8-9 kDa and smear bands, respectively. However, an antibody specific for the C-terminus presented as smears in GSS, with no PrPres detected in GPIALP. It was difficult to detect PrPres in V180I CJD. Collectively, our findings demonstrate the possibility of detecting PrPres in FFPE and classifying the prion disease types. This approach facilitates histopathological and biochemical evaluation in the same sample and is safe owing to the inactivation of infectivity. Therefore, it may be valuable for the diagnosis and research of prion diseases.

Increased expression of human antiviral protein MxA in FUS proteinopathy in amyotrophic lateral sclerosis

FUS mutations are one of the major mutations in familial amyotrophic lateral sclerosis (ALS). The pathological hallmark is FUS-positive neuronal cytoplasmic inclusions (FUS-NCI), known as FUS proteinopathy. Human myxovirus resistance protein 1 (MxA) is an IFN-induced dynamin-like GTPase that acts as antiviral factor. In this study, we examined the expression of MxA in neurons bearing FUS-NCI. We performed immunohistochemistry for FUS and MxA to examine the expression of MxA in two autopsy cases with different FUS gene mutations localized at the nuclear localization signal site (Case 1, H517P; Case 2, R521C). MxA. Most neurons bearing FUS-NCI have increased cytoplasmic MxA expression. Increased cytoplasmic MxA showed several distribution patterns in relation to FUS-NCIs such as the following: colocalization with NCI, distribution more widely than NCI, and different distribution peaks from NCI. Our results suggested that antiviral signaling IFNs are involved upstream in the formation of FUS-NCI in ALS-FUS patients.

Ribosomal protein SA is a common component of neuronal intranuclear inclusions in polyglutamine diseases and Marinesco bodies

Neuronal intranuclear inclusions (NIIs) are common key structures in polyglutamine (polyQ) diseases such as Huntington disease (HD), spinocerebellar ataxia type 1 (SCA1), and SCA3. Marinesco bodies (MBs) of dopaminergic neurons in the substantia nigra are also intranuclear structures and are frequently seen in normal elderly people. Ribosomal dysfunction is closely related to two differential processes; therefore, we aimed to identify the pathological characteristics of ribosomal protein SA (RPSA), a ribosomal protein, in both states. To this end, we evaluated the autopsy findings in four patients with HD, two SCA3, and five normal elderly cases (NCs). Immunohistochemical studies demonstrated that both NIIs and MBs contain RPSA. In polyQ diseases, RPSA was co-localized with polyQ aggregations, and 3D-reconstructed images revealed their mosaic-like distribution. Assessments of the organization of RPSA and p62 in NIIs showed that RPSA was more localized toward the center than p62 and that this unique organization was more evident in the MBs. Immunoblotting of the temporal cortices revealed that the nuclear fraction of HD patients contained more RPSA than that of NCs. In conclusion, our study revealed that RPSA is a common component of both NIIs and MBs, indicating that a similar mechanism contributes to the formation of polyQ NIIs and MBs.

Mutated FUS in familial amyotrophic lateral sclerosis involves multiple hnRNPs in the formation of neuronal cytoplasmic inclusions

Fused in sarcoma (FUS), coded by FUS, is a heterogeneous nuclear ribonucleoprotein (hnRNP). FUS mutations are among the major mutations in familial amyotrophic lateral sclerosis (ALS-FUS: ALS6). The pathological hallmarks of ALS-FUS are FUS-positive neuronal cytoplasmic inclusions (NCI). We examined various hnRNPs in FUS NCIs in the hippocampus in ALS-FUS cases with different FUS mutations (Case 1, H517P; Case 2, R521C). We also examined TDP43-positive NCIs in sporadic ALS hippocampi. Immunohistochemistry was performed using primary antibodies against FUS, p-TDP43, TDP43, hnRNPA1, hnRNPD, PCBP1, PCBP2, and p62. Numerous FUS inclusions were found in the hippocampal granule and pyramidal cell layers. Double immunofluorescence revealed colocalization of FUS and p-TDP43, and FUS and PCBP2 (p-TDP43/FUS: 64.3%, PCBP2/FUS: 23.9%). Colocalization of FUS and PCBP1, however, was rare (PCBP1/FUS: 7.6%). In the hippocampi of patients with sporadic ALS, no colocalization was observed between TDP43-positive inclusions and other hnRNPs. This is the first study to show that FUS inclusions colocalize with other hnRNPs, such as TDP43, PCBP2, and PCBP1. These findings suggest that in ALS-FUS, FUS inclusions are the initiators, followed by alterations of multiple other hnRNPs, resulting in impaired RNA metabolism.

Amyotrophic lateral sclerosis with TDP-43 abnormalities exhibiting globular glial tau inclusions in frontotemporal lobes and pallido-nigral system

Here we present the autopsy case of an 80-year-old woman with a 9-year history of motor neuron disease and atypical Parkinsonism. Her initial symptom was gait disturbance, and she subsequently developed limb weakness and Parkinsonism without response to levodopa. Her motor symptoms progressed to bulbar palsy, and she died of respiratory failure. Postmortem examination revealed characteristic findings of amyotrophic lateral sclerosis (ALS), including motor neuronal loss with astrogliosis, corticospinal tract degeneration, and TAR DNA-binding protein of 43 kDa abnormalities, including nuclear loss and skein-like inclusions. In contrast, severe tau pathological changes were seen in the frontotemporal lobes and pallido-nigral system. Tau pathologies affected not only neuronal components, such as neurofibrillary tangles and neuropil threads, but also glial cells (astrocytes and oligodendrocytes). Some glial tau pathologies exhibited peculiar round accumulations, reminiscent of globular glial inclusions (GGIs) in globular glial tauopathy. This unique autopsy case demonstrates that ALS with TDP-43 could be comorbid with globular glial tau inclusions and indicates that common pathological mechanisms exist among ALS and GGI formation.

Silence of resident microglia in GPI anchorless prion disease and activation of microglia in Gerstmann-Sträussler-Scheinker disease and sporadic Creutzfeldt-Jakob disease

GPI anchorless prion diseases (GPIALPs) show numerous coarse prion protein (PrP) deposits in the CNS but neuropil spongiform changes are mild and the incidence of dementia is low. Here, we examined differences in resident microglial phenotypes between GPIALP (D178fs25) and the other prion diseases Gerstmann-Sträussler-Scheinker (GSS) disease and sporadic Creutzfeldt-Jakob disease (sCJD) with respect to homeostasis and activation. Immunohistochemistry was performed on 2 GPIALP (D178fs25), 4 GSS (P102L), and 4 sCJD cases. Homeostatic microglia expressing TMEM119 and P2RY12 were preserved in GPIALP compared to GSS and sCJD. Microglia/macrophage activation in GSS and sCJD was associated with the extent of spongiform change. Immunoelectron microscopy revealed TMEM119 and P2RY12 in PrP plaque cores. Activated microglia/macrophages expressing HLA-DR and CD68 were predominant in GSS and sCJD whereas in GPIALP, homeostatic microglia were retained and activated microglia/macrophages were rarely observed. These data suggest that PrP deposition in GPIALP is less toxic and that microglia may be immune-tolerant to PrP deposition. This may be associated with milder tissue damage and a low incidence of dementia. Whereas microglia/macrophage activation is considered to be a reaction to tissue injury, this study shows that the degree of microglia/macrophage activity might influence the extent of tissue damage.

Neuropathology of classic myotonic dystrophy type 1 is characterized by both early initiation of primary age-related tauopathy of the hippocampus and unique 3-repeat tauopathy of the brainstem

Myotonic dystrophy type 1 (DM1) is an inherited autosomal-dominant condition that induces altered splicing of transcripts, including MAPT, leading to a distinctive abnormal deposition of tau protein in the CNS. We characterized the tau isoforms of abnormal depositions in the brains of 4 patients with classic DM1 by immunohistochemistry using isoform-specific antibodies. All patients, including those of presenile age, showed numerous neurofibrillary tangles (NFTs) of both 3-repeat and 4-repeat tau in the limbic area and mild involvement in the cerebral cortex. Amyloid-β deposition was only seen in 1 senile case while cortical tauopathy in all other cases was consistent with primary age-related tauopathy (PART). In the putamen and globus pallidus, only a few tau deposits were observed. Tau deposits in the brainstem frequently showed a DM1-specific pattern with 3-repeat tau dominant NFTs. Additionally, tau-positive astrocytes morphologically similar to tufted astrocytes and astrocytic plaques were occasionally observed in the brainstem; however, they were predominantly composed of 3-repeat tau. Thus, the classic DM1 showed both early onset of PART-like pathology in the limbic areas as a progeroid syndrome of DM1 and an abnormal splicing event in the brainstem leading to 3-repeat tau dominant accumulation with both neuronal and astrocytic involvement.

Early and extensive alterations of glial connexins, distal oligodendrogliopathy type demyelination, and nodal/paranodal pathology are characteristic of multiple system atrophy

The pathological hallmark of multiple system atrophy (MSA) is aberrant accumulation of phosphorylated α-synuclein in oligodendrocytes, forming glial cytoplasmic inclusions (GCIs). Extensive demyelination occurs particularly in the olivopontocerebellar and striatonigral pathways, but its precise mechanism remains elusive. Glial connexins (Cxs), which form gap junction channels between astrocytes and oligodendrocytes, play critical roles in myelin maintenance, and have not been studied in MSA. Therefore, we immunohistochemically investigated glial Cx changes in the cerebellar afferent fibers in 15 autopsied patients with MSA. We classified demyelinating lesions into three stages based on Klüver-Barrera staining: early (Stage I), intermediate (Stage II), and late (Stage III) stages showing subtle, moderate, and severe myelin reduction, respectively. Myelin-associated glycoprotein, but not myelin oligodendrocyte glycoprotein, was preferentially decreased in Stage I, suggesting distal oligodendrogliopathy type demyelination. Accumulation of phosphorylated α-synuclein in oligodendrocytes was frequently seen in Stage I but less frequently observed in Stages II and III. Tubulin polymerization-promoting protein (TPPP/p25α)-positive oligodendrocytes were preserved in Stage I but successively decreased in Stages II and III. Even at Stage I, Cx32 was nearly absent from myelin, despite the relative preservation of other nodal proteins, such as neurofascin, claudin-11/oligodendrocyte-specific protein, and contactin-associated protein 1, which successively decreased in the later stages. Cx32 was re-distributed in the oligodendrocyte cytoplasm and co-localized with GCIs. Cx47 gradually decreased at the oligodendrocyte surface in a stage-dependent manner but was not co-localized with GCIs. Astrocytic Cx43 was down-regulated in Stage I but up-regulated in Stages II and III, reflecting astrogliosis. Cx43/Cx47 gap junctions significantly decreased from Stage I to III. Activated microglia/macrophages and T cells infiltrated in Stage I rather than Stages II and III. Therefore, early and extensive alterations of glial Cxs, particularly Cx32 loss, occur in MSA and may accelerate distal oligodendrogliopathy type demyelination and nodal/paranodal dysfunction through disruption of inter-glial communication.

Characteristic distribution and molecular properties of normal cellular prion protein in human endocrine and exocrine tissues

Prion disease is an infectious and fatal neurodegenerative disease. Human prion disease autopsy studies have revealed abnormal prion protein (PrPSc) deposits in the central nervous system and systemic organs. In deer, chronic wasting disease has also become a global problem, with PrPSc in saliva and feces. Therefore, understanding normal cellular prion proteins (PrPc) characteristics in human systemic organs is important since they could be a PrPSc source. This study used western blotting and immunohistochemistry to investigate endocrine and exocrine tissues, such as the human pituitary, adrenal, submandibular glands and the pancreas. All tissues had 30–40 kDa PrP signals, which is a slightly higher molecular weight than normal brain tissue. Most cytoplasmic PrP-positive adenohypophyseal cells were immunopositive for nuclear pituitary-specific positive transcription factor 1. The adrenal medulla and islet cells of the pancreas were PrP-positive and colocalized with chromogranin A. The duct epithelium in the submandibular gland and pancreas were immunopositive for PrP. This study reports the characteristic molecular properties and detailed tissue localization of PrPc in endocrine and exocrine tissues, which is important for infection control and diagnosis.

Chronological Changes in the Expression Pattern of Hippocampal Prion Proteins During Disease Progression in Sporadic Creutzfeldt-Jakob Disease MM1 Subtype

The differential effects of sporadic Creutzfeldt-Jakob disease (sCJD) on the hippocampus and other neocortical areas are poorly understood. We aimed to reveal the histological patterns of cellular prion protein (PrPC) and abnormal prion protein (PrPSc) in hippocampi of sCJD patients and normal controls (NCs). Our study examined 18 postmortem sCJD patients (MM1, 14 cases; MM1 + 2c, 3 cases; MM1 + 2t, 1 case) and 12 NCs. Immunohistochemistry was conducted using 4 primary antibodies, of which 3 targeted the N-terminus of the prion protein (PrP), and 1 (EP1802Y) targeted the C-terminal domain. PrPC expression was abundant in the hippocampus of NCs, and the distribution of PrPC at CA3/4 was reminiscent of synaptic complexes. In sCJD cases with a disease history of <2 years, antibodies against the N-terminus could not detect synapse-like PrP expression at CA4; however, EP1802Y could characterize the synapse-like expression. PrPSc accumulation and spongiform changes became evident after 2 years of illness, when PrPSc deposits were more noticeably detected by N-terminal-specific antibodies. Our findings highlighted the chronology of histopathological alterations in the CA4 region in sCJD patients.

Longitudinal Changes of Tongue Thickness and Tongue Pressure in Neuromuscular Disorders

Background

Swallowing dysfunction is related to major cause of adverse events and an indicator of shorter survival among patients with neuromuscular disorders (NMD). It is critical to assess the swallowing function during disease progression, however, there are limited tools that can easily evaluate swallowing function without using videofluoroscopic or videoendoscopic examination. Here, we evaluated the longitudinal changes in tongue thickness (TT) and maximum tongue pressure (MTP) among patients with amyotrophic lateral sclerosis (ALS), myotonic dystrophy type 1 (DM1), and Duchenne muscular dystrophy (DMD).

Methods

Between 2010 and 2020, TT and MTP were measured from 21 ALS, 30 DM1, and 14 DMD patients (mean ages of 66.9, 44.5, and 21.4 years, respectively) at intervals of more than half a year. TT was measured, by ultrasonography, as the distance from the mylohyoid muscle raphe to the tongue dorsum, and MTP was determined by measuring the maximum compression on a small balloon when pressing the tongue against the palate. Then we examined the relationship between these evaluations and patient background and swallowing function.

Results

Mean follow-up periods were 24.0 months in the ALS group, 47.2 months in the DM1group, and 61.1 months in the DMD group. The DMD group demonstrated larger first TT than the other groups, while the DM1 group had lower first MTP than the ALS group. The ALS group showed a greater average monthly reduction in mean TT than the DM1 group and greater monthly reductions in mean body weight (BW) and MTP than the other groups. Significant differences between the first and last BW, TT, and MTP measures were found only in the ALS group.

Conclusions

This study suggests that ALS is associated with more rapid degeneration of tongue function over several years compared to DMD and DM1.

Transactivation response DNA-binding protein of 43 kDa proteinopathy and lysosomal abnormalities in spastic paraplegia type 11

Spastic paraplegia type 11 (SPG11) is the most common autosomal recessive hereditary spastic paraplegia with thinning of the corpus callosum. Spatacsin, a protein encoded by the SPG11 gene, is associated with autophagy. SPG11 patients show spastic paraplegia, intellectual disability, dementia, and parkinsonism. A previous neuropathological analysis of SPG11 cases reported neurodegeneration mimicking amyotrophic lateral sclerosis without transactivation response DNA-binding protein of 43 kDa (TDP-43) deposits and unique sequestosome 1 (SQSTM1)-positive neuronal inclusions. We performed a neuropathological examination of two Japanese patients with complicated spastic paraplegia with thinning of the corpus callosum from different families, and one was genetically diagnosed as having SPG11. Both cases showed diffuse atrophy of the brain and spinal cord. Depigmentation of the substantia nigra was also observed. Immunohistochemistry revealed widespread distribution of areas showing TDP-43 aggregation in the central nervous system. The TDP-43 deposits in the thalamus and substantia nigra especially resembled skein-like inclusions. Unique SQSTM1-positive neuronal inclusions, as previously reported, were widespread in the whole central nervous system as well as the dorsal root ganglia. Double-labeling immunofluorescence of the dorsal root ganglia revealed that the unique, large SQSTM1-positive cytoplasmic inclusions of the ganglion cells were labeled with lysosome-associated membrane protein 1 and lysosome-associated membrane protein 2. This is the first report showing TDP-43 pathology in SPG11. The common neuropathological findings of TDP-43-positive inclusions in both the cases imply a causal connection between the TDP-43 proteinopathy and autophagy dysfunction in SPG11.

Abnormal prion protein deposits with high seeding activities in the skeletal muscle, femoral nerve, and scalp of an autopsied case of sporadic Creutzfeldt-Jakob disease

We report the general autopsy findings of abnormal prion protein (PrP) deposits with their seeding activities, as assessed by the real-time quaking-induced conversion (RT-QuIC) method, in a 72-year-old female patient with sporadic Creutzfeldt-Jakob disease (sCJD). At 68 years of age, she presented with gait disturbance and visual disorders. Electroencephalography showed periodic synchronous discharge. Myoclonus was also observed. A genetic test revealed that PRNP codon 129 was methionine/methionine (MM). She died of pneumonia three years and four months after disease onset, and a general autopsy was performed. The brain weighed 650 g and appeared markedly atrophic. Immunohistochemistry for PrP revealed synaptic PrP deposits and coarse PrP deposits in the cerebral cortices, basal ganglia, cerebellum, and brainstem. Western blot analysis identified type 1 proteinase-K-resistant PrP in frontal cortex samples. PrP deposits were also observed in systemic organs, including the femoral nerve, psoas major muscle, abdominal skin, adrenal medulla, zona reticularis of the adrenal gland, islet cells of the pancreas, and thyroid gland. The RT-QuIC method revealed positive seeding activities in all examined organs, including the frontal cortex, femoral nerve, psoas major muscle, scalp, abdominal skin, adrenal gland, pancreas, and thyroid gland. The following 50% seeding dose (SD₅₀ ) values were 9.5 (frontal cortex); 8 ± 0.53 (femoral nerve); 7 ± 0.53 (psoas major muscle); and 7.88 ± 0.17 (scalp). The SD₅₀ values for the adrenal gland, dermis, pancreas, and thyroid gland were 6.12 ± 0.53, 5.25, 4.75, and 4.5, respectively. PrP deposits in general organs may be associated with long-term disease duration. This case indicated the necessity for general autopsies in sCJD cases to establish strict infection control procedures for surgical treatment and to examine certain organs.

Symmetrical glial hyperplasia in the brainstem of fibrodysplasia ossificans progressiva

Fibrodysplasia ossificans progressiva (FOP) is a rare autosomal dominant disease, characterized by the progressive ossification of skeletal muscles, fascia, tendons, and ligaments. In most cases, the great toes of patients show symmetrical congenital malformations. The causative gene for FOP has been identified as the activin A receptor, type 1 (ACVR1) gene (ACVR1). The ACVR1 R206H mutation is the most common mutation among FOP patients, and the ACVR1 G356D mutation has been identified as a rare mutation in a Japanese FOP patient with slow progression. In addition to musculoskeletal abnormalities, a series of autopsy studies described one FOP case, without genetic testing to identify ACVR1 mutation, showing nodular heterotopia at the edge of the fourth ventricle. Here, we report the general autopsy findings for a 75-year-old man with FOP, caused by the ACVR1 G356D mutation, including the precise examination of brainstem lesions. Postmortem examination revealed unique symmetrical glial hyperplasia of the pons and medulla oblongata. Microscopically, lesions of the pons involving residual neurons and lesions of the medulla oblongata consisted of subependymal cells. Immunohistochemical analysis of these lesions revealed developmental anomalies, with different cellular components. In this report, for the first time, we present the neuropathological description of a patient with genetically confirmed FOP and symmetrical glial hyperplasia of the pons and medulla oblongata. The presented pathological findings, in conjunction with previous reports implying that the glial hyperplasia of the brainstem is common in FOP, suggest that ACVR1 may play an unclarified developmental role in the human brainstem.

PCBP2 Is Downregulated in Degenerating Neurons and Rarely Observed in TDP-43-Positive Inclusions in Sporadic Amyotrophic Lateral Sclerosis

Various heterogeneous nuclear ribonucleoproteins (hnRNPs) are deposited in pathological inclusions of amyotrophic lateral sclerosis (ALS) and related diseases, such as frontotemporal lobar degeneration (FTLD). Recently, poly (rC)-binding protein 2 (PCBP2, hnRNP-E2), a member of the hnRNP family, was reported to be colocalized with transactivation-responsive DNA-binding protein 43 kDa (TDP-43)-immunopositive inclusions in cases of FTLD-TDP. Here, we used immunohistochemical methods to investigate PCBP1 and PCBP2 expression in the spinal cords of sporadic ALS patients, with special reference to TDP-43-positive inclusions. Thirty autopsy cases of sporadic ALS were examined by immunohistochemistry using antibodies against PCBP1, PCBP2, sequestosome 1 (p62), and TDP-43. In control subjects without neurological disorders, neurons predominantly expressed PCBP2, rather than PCBP1, in their cytoplasm and nuclei. Anterior horn cells of sporadic ALS patients often had various levels of PCBP2 expression, and motor neurons with skein-like inclusions often had reduced or lost cytoplasmic and nuclear PCBP2 staining. Notably, one case with FTLD-TDP subtype B pathology had marked colocalization of TDP-43 and PCBP2 in the cytoplasmic inclusions and dystrophic neurites of the cerebral cortex, hippocampus, and spinal cord. In conclusion, PCBP2 was reduced in anterior horn cells of sporadic ALS, but its occurrence in TDP-43 inclusions was a rare phenomenon.

Relationship between tongue pressure and functional oral intake scale diet type in patients with neurological and neuromuscular disorders

INTRODUCTION

Patients with neurological and neuromuscular disorders (NNMD) frequently experience swallowing disorders that increase aspiration pneumonia risk and therefore require specialized diets or tube feeding. Diet type level usually is assessed by video fluoroscopic swallowing study (VFSS). To identify a simpler assessment method, we examined the association between diet type (based on the Functional Oral Intake Scale [FOIS]) diet type and maximum tongue pressure (MTP).

METHODS

From 2011-2020, FOIS diet type level and MTP were assessed in a sample of 927 patients. Of these patients, 186 had Parkinson's disease (PD), 69 had Parkinson-related disease (PRD), 61 had multiple system atrophy (MSA), 42 had spinocerebellar degeneration (SCD), 147 had amyotrophic lateral sclerosis (ALS), 180 had myotonic dystrophy type 1 (DM1), and 242 had Duchenne muscular dystrophy (DMD). VFSS was conducted while patients swallowed water and foods containing barium. MTP measurements were collected the same day. Participants' diet type level was adjusted based on the VFSS, with some participants requiring multiple examinations. Relationships between diet type level and MTP were tested using univariate and Spearman rank correlation analyses.

RESULTS

Mean MTP for the entire NNMD group (25.5 ± 13.1 kPa) was lower than that of healthy elderly individuals, as determined in previous reports. The highest MTP was found in the MSA group (32.2 ± 15.7 kPa) and the lowest in the DM1 group (19.1 ± 9.0 kPa). Diet type level was highest in the MSA group (5.8 ± 1.4) and lowest in the DMD group (5.2 ± 1.7). A significant correlation was observed between diet type level and MTP (R = 0.384, p < 0.001). The optimum MTP cutoff values-detected using ROC curves to predict a requirement to change to a dysphagia diet-was highest in the DMD group (29.0 kPa) and lowest in the ALS group (12.3 kPa).

CONCLUSIONS

The decision to change NNMD patients to a dysphagia diet can be made based on MTP. Modifying a patient's oral diet (FOIS level ≤ 5) should be considered for those with a MTP of 10-25 kPa, with the cutoff value varying by disease.

Frequent Detection of Pituitary-Derived PrPres in Human Prion Diseases

Human prion diseases including sporadic Creutzfeldt-Jakob disease (sCJD), inherited prion diseases, and acquired human prion diseases are lethal neurodegenerative diseases. One of the major sources of iatrogenic Creutzfeldt-Jakob disease was human growth hormone (hGH-iCJD) derived from contaminated cadaveric pituitaries. The incidence of hGH-iCJD has decreased since changing from growth hormone extracted from human cadaveric pituitaries to recombinant pituitary hormones. However, extensive analysis on the localization and detecting of abnormal prion protein in the pituitary gland are limited. In this study, we examined 9 autopsied brains and pituitary glands from 6 patients with prion disease (3 Gerstmann-Sträussler-Scheinker disease, 2 sCJD, and 1 dura mater graft-associated CJD) and 3 individuals with nonprion diseases. Western blot analysis of pituitary samples demonstrated unique glycoforms of normal cellular prion protein with molecular weights of 30–40 kDa, which was higher than the typical 25–35 kDa prion protein in brains. Proteomic analysis also revealed prion protein approximately the molecular weight of 40 kDa in pituitary samples. Moreover, proteinase K-resistant Prion protein was frequently detected in pituitary samples of the prion diseases. Immunohistochemistry for Prion protein revealed mosaic cellular distribution preferentially in growth hormone- or prolactin-producing cells.

Dynactin is involved in Lewy body pathology

Dynactin forms a protein complex with dynein that retrogradely transports cargo along microtubules. Dysfunction of this dynein-dynactin complex causes several neurodegenerative diseases such as Perry syndrome, motor neuron diseases and progressive supranuclear palsy. Recently, we reported colocalization of phosphorylated α-synuclein (p-SNCA) and the largest subunit of dynactin (DCTN1) in Lewy body (LB)-like structures in Perry syndrome. Previous reports have not focused on the relationship between dynactin and synucleinopathies. Thus, we examined autopsied human brains from patients with Parkinson's disease, dementia with LBs, and multiple system atrophy using immunohistochemistry for p-SNCA, DCTN1, dynactin 2 (DCTN2, dynamitin) and dynein cytoplasmic 1 intermediate chain 1 (DYNC1I1). We also examined microtubule affinity-regulating kinases (MARKs), which phosphorylate microtubule-associated proteins and trigger microtubule disruption. Both brainstem-type and cortical LBs were immunopositive for DCTN1, DCTN2, DYNC1I1 and p-MARK and their staining often overlapped with p-SNCA. Lewy neurites were also immunopositive for DCTN1, DCTN2 and DYNC1I1. However, p-SNCA-positive inclusions of multiple system atrophy, which included both glial and neuronal cytoplasmic inclusions, were immunonegative for DCTN1, DCTN2, DYNC1I1 and p-MARK. Thus, immunohistochemistry for dynein-dynactin complex molecules, especially DCTN1, can clearly distinguish LBs from neuronal cytoplasmic inclusions. Our results suggest that dynactin is closely associated with LB pathology.

DCTN1 F52L mutation case of Perry syndrome with progressive supranuclear palsy-like tauopathy

INTRODUCTION

Perry syndrome is a rapidly progressive, autosomal dominant parkinsonism characterized by central hypoventilation, depression and severe weight loss. To date, eight DCTN1 mutations have been identified associated with Perry syndrome. A novel F52L DCTN1 mutation case of Perry syndrome is characterized by late-onset parkinsonism and frontotemporal atrophy.

METHODS

A Japanese woman suffered from slowly progressing parkinsonism since age 48. At age 59, she developed central hypoventilation, and required breathing assistance. Gene analysis identified a p.F52L mutation in DCTN1 and she was diagnosed with Perry syndrome. She died of aspiration pneumonia at age 74.

RESULTS

Postmortem examination revealed severe neuronal loss in the substantia nigra and the putamen. Immunohistochemistry for DCTN1 revealed many abnormal aggregates, mainly in neurons in the brainstem and basal ganglia. Additionally, numerous abnormal phosphorylated tau deposits including neurofibrillary tangles, tuft-shaped astrocytes and coiled bodies were observed mainly in the basal ganglia, brainstem and cerebellum. These correspond with the neuropathologic criteria for progressive supranuclear palsy. Colocalization of DCTN1 and tau were occasionally seen. Colocalization of phosphorylated α-synuclein and DCTN1 were also observed in Lewy body-like structures in oculomotor nuclei. Phosphorylated TARDBP-positive neuronal cytoplasmic inclusions were few.

CONCLUSION

In conjunction with long disease duration and aging, our findings suggest that the F52L DCTN1 mutation may evoke severe tauopathy and moderate α-synucleinopathy.

Echocardiography versus (201)Tl semi-quantitative gated single photon emission tomography for the evaluation of cardiac disease associated with late stage Duchenne muscular dystrophy

OBJECTIVE

In Duchenne muscular dystrophy (DMD) patients cardiac abnormalities are often detected. In adult DMD patients cardiac disease (CD) is a cause of death which increases by age and is related to respiratory dysfunction. Studies have demonstrated that CD in early DMD can be detected by echocardiography (EC) or semi-quantitative gated single photon emission tomography ((201)Tl SQGS), and the accuracy of these two tests is similar. As the disease advances, evaluation of CD by EC becomes difficult due to thoracic deformity and scoliosis. We compared (201)Tl SQGS and EC in the evaluation of cardiac function in late stage DMD, based on the ejection fraction (EF) value calculated by both tests. Twenty-three males with late stage DMD, 12 to 35 years of age (22.2±7.5), were studied by (201)Tl SQGS and EC. The mean EF value by (201)Tl SQGS was 60.8%±14.1%, which differed from that obtained by EC (52.7%±9.8%, P=0.003). Eleven patients less than 20 years old did not demonstrate a significant difference between the two tests (P=0.06), however, 12 patients over 20 years of age had significantly different results between tests (P=0.002).

CONCLUSION

Although our patients were few we indicated that in DMD patients, aged older than 20 years, at an advanced stage of the disease, the EF values calculated by EC were lower than those by (201)Tl SQGS possibly due to thoracic deformity.

[An autopsy case of amyotrophic lateral sclerosis with ampulla cardiomyopathy]

We herein report an autopsy case of a 63-year-old man with amyotrophic lateral sclerosis (ALS) who developed "ampulla cardiomyopathy." At the age of 56, he noticed a progressive weakness in his right upper extremity. One year later, a progressive weakness of the left upper extremity began. Dropped head and progressive weakness of the lower extremities emerged at the ages of 61 and 62, respectively. Intravenous immunoglobulin and plasma-exchange therapies did not improve his weakness. At the age of 63, one month before his death, he was hospitalized due to aspiration pneumonia. A tracheostomy was performed to secure his airway. Four days after the operation, an ST elevation of his electrocardiogram was incidentally found on the ECG monitor. An echocardiogram revealed diffuse hypokinesia of the wall of the left ventricle except in the basal portion, which is the typical finding of "ampulla cardiomyopathy." Wall motion of the left ventricle improved and his circulatory condition was stabilized after treatment, but his condition thereafter worsened again and he died 3 weeks later. An autopsy examination revealed diffuse fibrosis and degeneration of the cardiomyofibers. Neuropathological examination revealed neuronal cell loss, Bunina bodies and skein-like inclusions in the hippoglossal nuclei. In the thoracic spinal cord, degenarated anterior horn cells were seen and macrophage permeation in the corticospinal tract were shown by CD68 immunostaining. Therefore, the final neuropathological diagnosis was ALS. This report is the first autopsy case of ALS complicated with "ampulla cardiomyopathy."

Novel missense mutations in the human lysosomal sialidase gene in sialidosis patients and prediction of structural alterations of mutant enzymes

Three novel missense mutations in the human lysosomal sialidase gene causing amino acid substitutions (P80L, W240R. and P316S) in the coding region were identified in two Japanese sialidosis patients. One patient with a severe, congenital form of type 2 sialidosis was a compound heterozygote for 239C-to-T (P80L) and 718T-to-C (W240R). The other patient with a mild juvenile-onset phenotype (type 1) was a homozygote for the base substitution of 946C-to-T (P316S). None of these mutant cDNA products showed enzymatic activity toward an artificial substrate when coexpressed in galactosialidosis fibroblastic cells together with protective protein/cathepsin A (PPCA). All mutants showed a reticular immunofluorescence distribution when coexpressed with the PPCA gene in COS-1 cells, suggesting that the gene products were retained in the endoplasmic reticulum/Golgi area or rapidly degraded in the lysosomes. Homology modeling of the structural changes introduced by the mutations predicted that the P80L and P316S transversions cause large conformational changes including the active site residues responsible for binding the sialic acid carboxylate group. The W240R substitution was deduced to influence the molecular surface structure of a limited region of the constructed models, which was also influenced by previously identified V217M and G243R transversions.

Evidence for regulation of myelin protein synthesis by contact between adjacent Schwann cell plasma membranes

The spontaneously immortalized S16 Schwann cell line expresses higher levels of myelin-associated glycoprotein (MAG) and PO glycoprotein and their messenger RNAs when grown at high density than at low density [Sasagasako et al: J Neurochem 1996;66:1432-1439]. This up-regulation of myelin protein expression at high density is not associated with decreased cellular proliferation and may be caused by direct cell-to-cell contact. To investigate the hypothesis that increased mRNA levels for myelin proteins are caused by contact between Schwann cells, sparse S16 cell cultures were treated for 48 h with plasma-membrane-enriched fractions isolated from dense S16 cells. The treatment had no effect on the proliferation of the cells, but MAG and PO mRNAs were elevated 2- and 1.3-fold, respectively, in comparison to untreated cells. These effects on levels of myelin protein mRNAs were eliminated by pretreatment of the membrane fraction with heat or trypsin and were not caused by plasma membrane fractions from NIH 3T3 cells. These data support the hypothesis that homotypic contact between Schwann cells up-regulates expression of myelin proteins and suggest the possibility of autotypic contact-mediated regulation of myelinogenesis by adjacent spiraled membranes of individual Schwann cells.

Myelin gene expression in immortalized Schwann cells: relationship to cell density and proliferation

Myelin gene expression was investigated in the immortalized S16 Schwann cell line grown in the presence and absence of serum and at different densities. Protein expression was monitored by western blotting, and message levels were determined by RNase protection assays. To study cell proliferation rates at different cell densities and serum conditions, [3H]thymidine uptake assays and cell counts were performed. Although serum deprivation decreased cell proliferation as expected, the proliferation of S16 cells was unchanged or slightly increased at high density under the conditions of our experiments in either serum-containing or serum-free medium. This increased cell division at high density appeared to be due to greater release of an autocrine growth factor to the medium by dense cell populations. For both sparse and dense cells, substantially more P0 glycoprotein (P0) and myelin-associated glycoprotein (MAG) per milligram of total cellular protein were expressed when the cells were proliferating slowly in defined medium in comparison with more rapidly proliferating cells in serum-containing medium. Furthermore, in both serum-containing and defined media, dense cell populations expressed more MAG and PO than sparse ones. PO mRNa and MAG mRNA levels generally paralleled protein levels. The level of mRNA for peripheral myelin protein-22 (PMP-22) was also increased at high cell density but did not change much when proliferation was decreased by serum deprivation. PMP-22 protein was not detected under any of the growth conditions. The changes in expression of these genes with growth conditions may be specific for myelin proteins, because the expression of a nonmyelin glycoprotein, L1, remained constant. The level of cyclic AMP in the cells did not change with the different growth conditions tested. The results indicate that the S16 Schwann cell line mimics primary or secondary Schwann cells by down-regulating myelin gene expression when it proliferates more rapidly in the presence of serum. Furthermore, in both the presence and absence of serum, there was greater expression of myelin genes at high cell density that was not associated with a decreased proliferative rate. Because evidence for a role of secretory factors in affecting myelin gene expression was not obtained by treating sparse S16 cells with medium conditioned by dense S16 cells, the results suggest that the higher expression of myelin genes at high density may be mediated by cell-to-cell contact.

The synthetic pathway for glucosylsphingosine in cultured fibroblasts

The synthesis of glucosylsphingosine (GlcSph), a glucosylceramide (GlcCer) analogue devoid of fatty acids, in cultured fibroblasts was studied by using conduritol beta epoxide (CBE), an inhibitor of beta-glucosidase, and 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP), an inhibitor of glucosylceramide (GlcCer) synthase (glucosyltransferase). When CBE was added to the culture medium, the intracellular beta-glucosidase activity decreased, and both GlcCer and GlcSph accumulated in the cells. After the addition of PDMP, the concentration of GlcCer decreased, while the content of GlcSph increased. When CBE and PDMP were added together, the intracellular accumulation of GlcSph to decreased to less than when CBE alone was added. Based on these results, the synthetic pathway for GlcSph was thus considered to not only be through the glucosylation of sphingosine, but also through the deacylation of GlcCer. When GlcCer (d18:1, C12:0) was added to the culture medium, the intracellular accumulation of GlcSph (d18:1) was evident, and it was also more pronounced in the presence of CBE. In addition, when GlcCer (d18:0, C12:0) was used, apparent accumulation of GlcSph (d18:0) was also observed. In order to determine whether or not the deacylase of GlcCer is identical to acid ceramidase, a deacylase of ceramide, the same experiments were carried out using fibroblasts from two patients with Farber disease, in which acid ceramidase is genetically deficient. The accumulation of GlcSph in the Farber disease fibroblasts after the loading of GlcCer for 7 days was found to be one-fifth of the control level.(ABSTRACT TRUNCATED AT 250 WORDS)

Glucosylceramide and glucosylsphingosine metabolism in cultured fibroblasts deficient in acid beta-glucosidase activity

The metabolism of glucosylceramide (GlcCer) and glucosylsphingosine (GlcSph) was studied using cultured fibroblasts deficient in acid beta-glucosidase activity. In fibroblasts from patients with Gaucher's disease, in vitro beta-glucosidase activities were 2.7-11.7% and 4.8-13.6% of control values when 4-methylumbelliferyl beta-D-glucoside and GlcSph were used as substrates, respectively. In spite of the enzyme deficiency, GlcCer and GlcSph, the natural substrates of the deficient enzyme, did not accumulate in the cells. When normal fibroblasts were incubated with conduritol B epoxide (CBE), a specific inhibitor of acid beta-glucosidase, the in vitro enzyme activities decreased dose-dependently (2.2-2.4% of control values at 50 microM CBE), and GlcCer and GlcSph accumulated in the cells at concentrations of CBE higher than 50 microM. To investigate the intracellular metabolism of GlcCer and GlcSph, either radioactive GlcCer or GlcSph was loaded onto cultured fibroblasts. In fibroblasts treated with a high dose of CBE (1 mM), the degradation of GlcCer and GlcSph was retarded (5-21% on day 7; normal range, 81-99%), while in fibroblasts from patients with Gaucher's disease, both the pattern and rate of the degradation of the lipids (83-97% on day 7) were almost the same as those seen in the control cells. These results indicate that in Gaucher's disease fibroblasts the intracellular metabolism of GlcCer and GlcSph is normal in spite of the deficiency in beta-glucosidase activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Prenatal diagnosis of congenital sialidosis

A case of prenatally diagnosed congenital sialidosis is described in a 21-week-old male fetus, which was the fifth product of non-consanguineous parents. The proband, the second product, was diagnosed as having sialidosis by the enzyme assay in peripheral leukocytes after birth. At the 17th week of pregnancy, the fetus at risk was proven to have isolated sialidase deficiency after analyzing a sample of the cultured amniotic fluid cells. There were many cytoplasmic vacuoles and increased amounts of sialyloligosaccharides in the tissue of the aborted fetus, while the amount and the pattern of gangliosides in the central nervous system were normal.

[A family with MELAS whose main manifestations are maternally-transmitted deafness and diabetes mellitus]

A family with maternally-transmitted deafness and diabetes mellitus is described. Although the proband clinically exhibited MELAS-like symptoms such as sudden-onset cerebellar ataxia and weakness of the proximal portion of the limbs in addition to deafness and diabetes mellitus, the other three members of the family had only deafness and diabetes mellitus and no neurological manifestations. The analysis of mitochondrial DNA of the two members revealed an A-->G mutation of tRNA(leu(UUR)), a mutation commonly seen in patients with MELAS. According to the clinical histories and endocrinological investigations, the type of the diabetes mellitus in this family was considered to be IDDM, which may be attributed to the dysfunction of mitochondrial of the pancreas islet cells, resulting from the mutation of the mitochondrial DNA.

[Gadolinium-MRI findings of two adrenoleukodystrophy cases treated with gamma-globulin]

Two cases of adrenoleukodystrophy were reported. We treated them with intravenous gamma-globulin infusion. MRI with gadolinium enhancement was performed before and after the therapy to evaluate the effect of gamma-globulin. Case 1 was a 19-year-old boy, who noticed left hemianopsia when he was 18 years old. Case 2 was a 36-year-old man, who developed ataxic gait and character change when he was 33 years old. Very long chain fatty acids in plasma and RBC membrane were elevated in both cases. On T2-weighted image of MRI, high signal lesions were seen in the white matter of occipital lobe in case 1, cerebellum, internal capsule, and around the corpus callosum in case 2. On T1-weighted image, the rim of every lesion was enhanced by gadolinium infusion. After the gamma-globulin therapy, gadolinium enhancement of the rim remarkably reduced in case 1. No reduction was observed in case 2. MRI findings of case 1 indicate the possibility that gamma-globulin may suppress the inflammation of the adrenoleukodystrophy.