Analysis of splicing abnormalities in the white matter of myotonic dystrophy type 1 brain using RNA sequencing.

Myotonic dystrophy type 1 (DM1) is a neuromuscular disorder caused by the genomic expansion of CTG repeats, in which RNA-binding proteins, such as muscleblind-like protein, are sequestered in the nucleus, and abnormal splicing is observed in various genes. Although abnormal splicing occurs in the brains of patients with DM1, its relation to central nervous system symptoms is unknown. Several imaging studies have indicated substantial white matter defects in patients with DM1. Here, we performed RNA sequencing and analysis of CTG repeat lengths in the frontal lobe of patients with DM1, separating the gray matter and white matter, to investigate splicing abnormalities in the DM1 brain, especially in the white matter. Several genes showed similar levels of splicing abnormalities in both gray and white matter, with an observable trend toward an increased number of repeats in the gray matter. These findings suggest that white matter defects in DM1 stem from aberrant RNA splicing in both gray and white matter. Notably, several of the genes displaying abnormal splicing are recognized as being dominantly expressed in astrocytes and oligodendrocytes, leading us to hypothesize that splicing defects in the white matter may be attributed to abnormal RNA splicing in glial cells.

Clinical course of pathologically confirmed corticobasal degeneration and corticobasal syndrome.

The clinical presentation of corticobasal degeneration is diverse, while the background pathology of corticobasal syndrome is also heterogeneous. Therefore, predicting the pathological background of corticobasal syndrome is extremely difficult. Herein, we investigated the clinical findings and course in patients with pathologically, genetically and biochemically verified corticobasal degeneration and corticobasal syndrome with background pathology to determine findings suggestive of background disorder. Thirty-two patients were identified as having corticobasal degeneration. The median intervals from the initial symptoms to the onset of key milestones were as follows: gait disturbance, 0.0 year; behavioural changes, 1.0 year; falls, 2.0 years; cognitive impairment, 2.0 years; speech impairment, 2.5 years; supranuclear gaze palsy, 3.0 years; urinary incontinence, 3.0 years; and dysphagia, 5.0 years. The median survival time was 7.0 years; 50% of corticobasal degeneration was diagnosed as corticobasal degeneration/corticobasal syndrome at the final presentation. Background pathologies of corticobasal syndrome (n = 48) included corticobasal degeneration (33.3%), progressive supranuclear palsy (29.2%) and Alzheimer's disease (12.5%). The common course of corticobasal syndrome was initial gait disturbance and early fall. In addition, corticobasal degeneration-corticobasal syndrome manifested behavioural change (2.5 years) and cognitive impairment (3.0 years), as the patient with progressive supranuclear palsy-corticobasal syndrome developed speech impairment (1.0 years) and supranuclear gaze palsy (6.0 years). The Alzheimer's disease-corticobasal syndrome patients showed cognitive impairment (1.0 years). The frequency of frozen gait at onset was higher in the corticobasal degeneration-corticobasal syndrome group than in the progressive supranuclear palsy-corticobasal syndrome group [P = 0.005, odds ratio (95% confidence interval): 31.67 (1.46-685.34)]. Dysarthria at presentation was higher in progressive supranuclear palsy-corticobasal syndrome than in corticobasal degeneration-corticobasal syndrome [P = 0.047, 6.75 (1.16-39.20)]. Pyramidal sign at presentation and personality change during the entire course were higher in Alzheimer's disease-corticobasal syndrome than in progressive supranuclear palsy-corticobasal syndrome [P = 0.011, 27.44 (1.25-601.61), and P = 0.013, 40.00 (1.98-807.14), respectively]. In corticobasal syndrome, decision tree analysis revealed that 'freezing at onset' or 'no dysarthria at presentation and age at onset under 66 years in the case without freezing at onset' predicted corticobasal degeneration pathology with a sensitivity of 81.3% and specificity of 84.4%. 'Dysarthria at presentation and age at onset over 61 years' suggested progressive supranuclear palsy pathology, and 'pyramidal sign at presentation and personality change during the entire course' implied Alzheimer's disease pathology. In conclusion, frozen gait at onset, dysarthria, personality change and pyramidal signs may be useful clinical signs for predicting background pathologies in corticobasal syndrome.

An autopsy case of diffuse atypical argyrophilic grain disease (AGD) with presenile onset and three-year course of motor and cognitive impairment.

We report a case of argyrophilic grain disease (AGD) with unique clinical and pathological presentations. A 52-year-old man presented with spastic quadriparesis, bulbar palsy, and mild cognitive decline. His condition deteriorated rapidly and he died of pneumonia three years from onset. Pathologically, neuronal degeneration was involved severely in the amygdala, ambient gyrus, midbrain tegmentum, and reticular formation. The neurons of the temporal lobe, cingulate gyrus, brainstem, and spinal gray matter were also lost moderately. There was diffuse 4-repeat tau-pathology with argyrophilic grains. There were pretangles, globose-type neurofibrillary tangles, and coiled bodies in the cerebral cortices, basal ganglia, thalami, brainstem, and the spinal cord except for the cerebellar cortices. There was no pathologic mutation in MAPT.

[Antibody production capacity after COVID-19 vaccination in immune-mediated neuromuscular diseases under immunotherapy].

The post-vaccination antibody response in patients with immune-mediated neuromuscular diseases under immuno-suppressive therapy has not been sufficiently verified. The Japanese Society of Neurology has stated that coronavirus disease 2019 (COVID-19) vaccination should be given priority in patients with immunotherapy-associated neuromuscular diseases; however, data on antibody production to a novel mRNA vaccine are scarce in these patients. In this study, we aimed to measure residual antibody titers after the second dose and produced antibodies after the third dose of SARS-CoV-2 mRNA vaccine in 25 patients with neuromuscular diseases under immuno-suppressive therapy (disease group). We compared the disease group antibody titers with those of 829 healthy employees in our hospital (control group). The disease group included 17 patients with myasthenia gravis, 4 with multiple sclerosis, 3 with inflammatory muscle disease, and 1 with chronic inflammatory demyelinating polyneuropathies. Seven cases of the disease group showed negative antibody levels (<15.0 s/co) before the third vaccination, and antibody titers in the positive cases ranged from 16.9 to 4,589.0 s/co. Three of the seven antibody-negative cases turned positive after the third vaccination, and all but one of the antibody-positive cases showed a booster effect, with antibody titers after the third dose ranging from 245.1 to 85,374.0 s/co (1.0 to 885.0 times higher than those before vaccination). Although the immune response in the disease group was modest compared to the control group, in which antibody titers after the third vaccination ranged from 67.8 to 150,000 s/co (0.9 to 5,402.1 times higher than those before vaccination), the result indicated that a constant immune response was achieved under immuno-suppressive therapy. Even in the control group, three participants tested negative for residual antibody before the third inoculation, and four of the antibody-positive participants (27.7-24,054.0 s/co) lacked a booster effect after the third vaccination.

Guillain-Barré Syndrome Associated with COVID-19 in a Japanese Male.

April 2021 saw a widespread outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Osaka, Japan. We encountered the case of a 52-year-old man who had Guillain-Barré syndrome associated with coronavirus disease 2019 (COVID-19). After the relief of the respiratory symptoms owing to COVID-19, the patient experienced muscle weakness, which spread from his fingers to his extremities, and was unable to walk. Further examinations revealed mild protein elevation in the cerebrospinal fluid. In addition, nerve conduction studies showed demyelinating polyneuropathy, leading to the diagnosis of Guillain-Barré syndrome. After the administration of intravenous immunoglobulin and intravenous methylprednisolone, his symptoms drastically improved, and he was able to walk unaided 21 days after the onset of symptoms. On day 40, the patient was discharged with minimal muscle fatigue. Because Guillain-Barré syndrome associated with COVID-19 is expected to have a good prognosis, early diagnosis and treatment are important. Therefore, Guillain-Barré syndrome should be considered as a possible factor for muscle weakness during and after COVID-19 treatment.

Spinal muscular atrophy type 2 patient who survived 61 years: an autopsy case report.

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disease characterized by progressive muscle weakness due to degeneration of lower motor neurons in the anterior horn of the spinal cord. We analyzed autopsy findings of a male patient with SMA type 2 who survived until 61 years of age. Genetic analysis revealed a homozygous deletion of the survival motor neuron (SMN) gene 1 (SMN1) exon 7, confirming the diagnosis of SMA. Results of further analyses indicated that the patient had two copies of the genuine SMN gene 2 (SMN2) and one copy of a hybrid gene containing SMN2 exon 7 and SMN1 exon 8. Pathological examination revealed moderate neuronal loss of the anterior horn and appearance of heterotopic neurons in the lateral funiculus, whereas a few achromatic neurons were notably localized in the anterior horn of the lumbar segment. Microdysgenesis as a consequence of migration disturbance was found in the white matter of the frontal lobe, postulating the possibility of the maldevelopment of the nervous system.

Clinical trajectory of a patient with filaminopathy who developed arrhythmogenic cardiomyopathy, myofibrillar myopathy, and multiorgan tumors.

We report a case of a patient presenting with arrhythmogenic cardiomyopathy, myofibrillar myopathy, and multiorgan tumors. A 41-year-old woman with a history of hypertrophic cardiomyopathy, diagnosed at 6 years of age, developed scoliosis after puberty. Following spinal surgery to address the scoliosis, she developed recurrent severe arrhythmia and heart failure. She developed hypoventilation at age 29 years. Proximal dominant weakness and mild elevation of serum creatine kinase indicated possible myopathy. Myofibrillar myopathy was diagnosed by muscle biopsy at age 30 year. Acute abdomen was repeatedly reported from age 33 years, eventually leading to a diagnosis of gastric polyp and erosive ulcer. A urinary bladder tumor was found at age 35 years, and breast cancer was diagnosed at age 40 years. Whole exome sequencing detected a heterozygous missense mutation in Filamin C. Recent evidences suggest that filamins are associated with tumors, and this case further highlights the clinical spectrum of filaminopathy.

Transcriptome alterations in myotonic dystrophy frontal cortex.

Myotonic dystrophy (DM) is caused by expanded CTG/CCTG repeats, causing symptoms in skeletal muscle, heart, and central nervous system (CNS). CNS issues are debilitating and include hypersomnolence, executive dysfunction, white matter atrophy, and neurofibrillary tangles. Here, we generate RNA-seq transcriptomes from DM and unaffected frontal cortex and identify 130 high-confidence splicing changes, most occurring only in cortex, not skeletal muscle or heart. Mis-spliced exons occur in neurotransmitter receptors, ion channels, and synaptic scaffolds, and GRIP1 mis-splicing modulates kinesin association. Optical mapping of expanded CTG repeats reveals extreme mosaicism, with some alleles showing >1,000 CTGs. Mis-splicing severity correlates with CTG repeat length across individuals. Upregulated genes tend to be microglial and endothelial, suggesting neuroinflammation, and downregulated genes tend to be neuronal. Many gene expression changes strongly correlate with mis-splicing, suggesting candidate biomarkers of disease. These findings provide a framework for mechanistic and therapeutic studies of the DM CNS.

Age-dependent decline in remyelination capacity is mediated by apelin-APJ signaling.

Age-related regeneration failure in the central nervous system can occur as a result of a decline in remyelination efficacy. The responsiveness of myelin-forming cells to signals for remyelination is affected by aging-related epigenetic modification; however, the molecular mechanism is not fully clarified. In the present study, we report that the apelin receptor (APJ) mediates remyelination efficiency with age. APJ expression in myelin-forming cells is correlated with age-associated changes in remyelination efficiency, and the activation of APJ promotes remyelination through the translocation of myelin regulatory factor. APJ signaling activation promoted remyelination in both aged mice with toxin-induced demyelination and mice with experimental autoimmune encephalomyelitis. In human cells, APJ activation enhanced the expression of remyelination markers. Impaired oligodendrocyte function in aged animals can be reversibly reactivated; thus, the results demonstrate that dysfunction of the apelin-APJ system mediates remyelination failure in aged animals, and that their myelinating function can be reactivated by APJ activation.

Psychological Case Conference Following the Death of a Patient With Neuromuscular Disease: A Source of Emotional Support for Participating Medical Staff.

Healthcare professionals involved in the treatment and care of patients with intractable diseases, such as muscular dystrophy, increasingly encounter situations that can elicit emotional distress for them as well as the patients. Therefore, medical professionals also need support. This article describes a psychological case conference of multidisciplinary professionals involved in the treatment of a deceased patient with Duchenne muscular dystrophy. The conference aimed to support medical professionals in reflecting on and sharing their thoughts, feelings, and conflicts. Such a practice could support medical professionals in reflecting patients' thoughts and sharing their personal experiences with other staff members, which may alleviate emotional and personal conflicts. Reflecting on their interactions and dealings with patients serves this supportive function. Psychological case conferences for medical staff may serve as an opportunity for participants to feel emotionally supported and may perhaps help prevent burnout.

The secondary structural difference between Lewy body and glial cytoplasmic inclusion in autopsy brain with synchrotron FTIR micro-spectroscopy.

Lewy bodies (LBs) and glial cytoplasmic inclusions (GCIs) are specific aggregates found in Parkinson's disease (PD) and multiple system atrophy (MSA), respectively. These aggregates mainly consist of α-synuclein (α-syn) and have been reported to propagate in the brain. In animal experiments, the fibrils of α-syn propagate similarly to prions but there is still insufficient evidence to establish this finding in humans. Here, we analysed the protein structure of these aggregates in the autopsy brains of patients by synchrotron Fourier-transform infrared micro-spectroscopy (FTIRM) analysis without extracting or artificially amplifying the aggregates. As a result, we found that the content of the ß-sheet structure in LBs in patients with PD was significantly higher than that in GCIs in patients with MSA (52.6 ± 1.9% in PD vs. 38.1 ± 0.9% in MSA, P < 0.001). These structural differences may provide clues to the differences in phenotypes of PD and MSA.

[An autopsy case of elderly-onset herpes simplex encephalitis with acute respiratory failure caused by brainstem lesions].

An 89-year-old man was admitted because of persistent fever and impaired consciousness. On admission, his consciousness level was E3V3M4 according to the Glasgow Coma Scale. MRI of the brain showed high intensity lesions in the bilateral cingulate gyri. In the cerebrospinal fluid, both cell counts and glucose level were in the normal ranges. He had received antibiotics and intravenous isotonic saline. On the fifth day of hospitalization, blood examination revealed elevation of anti-herpes simplex virus (HSV) immunoglobulin M antibody, and herpes simplex encephalitis (HSE) was diagnosed. Despite treatment with acyclovir, his respiratory function and consciousness level deteriorated rapidly. On the eighth day, he died of respiratory failure. At autopsy, the brain showed multiple softenings of the gray and white matter in the hippocampus, amygdala, and temporal, insular, and cingulate cortices. Some of these lesions were hemorrhagic. Microscopic examination revealed that the lesions were necrotic and associated with perivascular inflammatory cell infiltration in the limbic system, hypothalamus, brainstem tegmentum area, and medulla. Eosinophilic intranuclear inclusions were rarely found in the astrocytes in the medulla. Immunohistochemistry revealed anti-HSV-1 antibody positive neurons in the brainstem tegmentum including reticular formation and the raphe nuclei. HSV-DNA was also detected in the postmortem cerebrospinal fluid. This was a rare case of HSE in which inflammation in the brainstem proved to be the cause of lethal respiratory failure.

Mitochondrial DNA enhance innate immune responses in neuromyelitis optica by monocyte recruitment and activation.

Although recent studies indicate the involvement of monocytes in accelerating the lesion formation of neuromyelitis optica spectrum disorder (NMOSD), the precise mechanism of the innate immune system activation remains elusive. Thus, in this study, we aimed to clarify the mechanisms of NMOSD pathogenesis from the viewpoint of innate immunity activation. We established anti-AQP4 recombinant autoantibodies (Ab) from plasmablasts in NMOSD patient's CSF. Human astrocytes treated with anti-AQP4 Ab produced a significant amount of CCL2 and contributed to the efficient recruitment of monocytes. Moreover, mitochondrial DNA (mtDNA), which activated monocytes via Toll-like receptor 9 (TLR9), was released from astrocytes treated with anti-AQP4 Ab. MtDNA further enhanced CCL2 production by monocytes, and it was demonstrated that mtDNA concentration correlated with the efficiency of monocyte recruitment in the CSF of NMOSD patients. In conclusion, these observations highlight that mtDNA which was released from astrocytes damaged by anti-AQP4 Ab has a central role in establishing the inflammatory loop of monocyte recruitment and activation via an innate immunity pathway.

Differences in splicing defects between the grey and white matter in myotonic dystrophy type 1 patients.

Myotonic dystrophy type 1 (DM1) is a multi-system disorder caused by CTG repeats in the myotonic dystrophy protein kinase (DMPK) gene. This leads to the sequestration of splicing factors such as muscleblind-like 1/2 (MBNL1/2) and aberrant splicing in the central nervous system. We investigated the splicing patterns of MBNL1/2 and genes controlled by MBNL2 in several regions of the brain and between the grey matter (GM) and white matter (WM) in DM1 patients using RT-PCR. Compared with amyotrophic lateral sclerosis (ALS, as disease controls), the percentage of spliced-in parameter (PSI) for most of the examined exons were significantly altered in most of the brain regions of DM1 patients, except for the cerebellum. The splicing of many genes was differently regulated between the GM and WM in both DM1 and ALS. In 7 out of the 15 examined splicing events, the level of PSI change between DM1 and ALS was significantly higher in the GM than in the WM. The differences in alternative splicing between the GM and WM may be related to the effect of DM1 on the WM of the brain.

Bile acid abnormality induced by intestinal dysbiosis might explain lipid metabolism in Parkinson's disease.

Intestinal dysbiosis refers to an imbalance in the intestinal flora. The concept of small intestinal bacterial overgrowth (SIBO), a condition of abnormal proliferation of the small intestine microbiota, has been proposed as a form of small intestine dysbiosis. In Parkinson's disease patients, weight loss and metabolic disorders such as lipid abnormalities are frequently encountered. This was a prospective investigation of the presence of SIBO using the lactulose breath test, Parkinson's disease symptoms, medications, abdominal symptoms, and blood data involving 39 Parkinson's disease patients. Of the 39 patients, 19 were positive for SIBO, 16 were negative, and 4 were equivocal. SIBO-positive patients had a significantly smaller dopaminergic drug load (dopamine replacement of Parkinson's disease drug potency) (P = 0.009) and significantly lower serum triglyceride (TG) (P = 0.024) and total bilirubin (P = 0.019) levels. No relationship was seen between the presence or absence of SIBO and motor or abdominal symptoms. The following hypothesis was developed with regard to the possibility that intestinal bacterial overgrowth has various effects that are exhibited via bile acid metabolism in Parkinson's disease patients. Serum bilirubin levels become higher as bilirubin metabolism declines with decreases in the intestinal bacteria. At the same time, bile acid is broken down due to increased intestinal bacteria, and lipid absorption decreases. This induces low serum TG levels and leads to weight loss. By a similar mechanism, there is less absorption of vitamin D as bile acid levels decrease, leading to osteoporosis and fractures. The possibility that some of the non-motor manifestations accompanying Parkinson's disease are caused by intestinal dysbiosis needs to be considered.

A clinicopathological study of ALS with L126S mutation in the SOD1 gene presenting with isolated inferior olivary hypertrophy.

We report an autopsy case of amyotrophic lateral sclerosis with L126S mutation in the superoxide dismutase 1 (SOD1) gene (SOD1). The patient was a 69-year-old Japanese man without relevant family history, who initially presented with slow progressive muscle weakness of the lower extremities without upper motor neuron signs, and died of respiratory failure 6 years after the onset. Neuropathological examination revealed a loss of lower motor neurons and degeneration of Clarke's column commensurate with that of the posterior spinocerebellar tract and the middle root zone of the posterior column. The primary motor area was minimally affected. Characteristic SOD1-immunopositive neuronal intracytoplasmic inclusions, mixed with neurofilament accumulation, were present in the affected areas. Isolated inferior olivary hypertrophy was observed, but did not involve the contralateral dentate nucleus, or the ipsilateral red nucleus and central tegmental tract, where no neuronal inclusions were found. In combination with data from a previous autopsy case, this study suggests that the L126S mutation may cause focal neuronal degeneration in the brainstem.

Increased number of mitochondria in capillaries distributed in stroke-like lesions of two patients with MELAS.

We investigated two autopsy cases of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) using immunohistochemical staining with an anti-mitochondrial antibody against translocase of the outer membrane 20 (TOMM20). In case 1, the patient was a 42-year-old man with a disease duration of 53 days, and in case 2, the patient was a 62-year-old woman with a disease duration of 27 months. In both the cases autopsy revealed moderate atrophy of the cerebrum and cerebellum and multifocal necrotizing lesions, irrespective of the vascular territory. Case 1 showed multiple areas with total necrosis in the cortex, accompanied by increases in number of protoplasmic astrocytes and acidophilic neurons as well as axonal swelling, suggestive of acute or subacute stage stroke-like lesions (SLLs). In case 2, most of the SLLs displayed laminar spongy change in a rarefied cortex, and were considered to be at the chronic stage. In both the cases, capillary proliferation was noted within the SLLs, particularly in the acute phase. Endothelial cells of proliferating capillaries were strongly positive for TOMM20. In the cortex outside the SLLs, microvessels displayed only a fine granular immunoreactivity, as is seen in the controls. Although smooth muscle cells and endothelial cells in pial arteries and arterioles were also strongly positive for TOMM20, the territories of the affected pial arteries and arterioles did not correlate with the distribution of the SLLs. Although MELAS is characterized by recurrent stroke-like episodes (SLEs), the pathogenetic relationship between SLEs and mitochondrial angiopathy remains unknown. An aberrant increase of mitochondria in the capillary endothelial cells of SLLs may disturb endothelial function, thus playing a role in the formation or development of SLLs.

Parkinson's disease is a type of amyloidosis featuring accumulation of amyloid fibrils of α-synuclein.

Many neurodegenerative diseases are characterized by the accumulation of abnormal protein aggregates in the brain. In Parkinson's disease (PD), α-synuclein (α-syn) forms such aggregates called Lewy bodies (LBs). Recently, it has been reported that aggregates of α-syn with a cross-ß structure are capable of propagating within the brain in a prionlike manner. However, the presence of cross-ß sheet-rich aggregates in LBs has not been experimentally demonstrated so far. Here, we examined LBs in thin sections of autopsy brains of patients with PD using microbeam X-ray diffraction (XRD) and found that some of them gave a diffraction pattern typical of a cross-ß structure. This result confirms that LBs in the brain of PD patients contain amyloid fibrils with a cross-ß structure and supports the validity of in vitro propagation experiments using artificially formed amyloid fibrils of α-syn. Notably, our finding supports the concept that PD is a type of amyloidosis, a disease featuring the accumulation of amyloid fibrils of α-syn.

Pathological Findings in Male Patients With Anti-N-methyl-d-Aspartate Receptor Encephalitis.

Anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis is the most common type of autoimmune encephalitis. The disease predominantly affects women (1:5-1:10), with only 3 reports of autopsy findings in women being published to date. The present study reports findings from the first autopsy performed on a man with anti-NMDAR encephalitis. The patient had some scattered lesions in the limbic system with neuronal loss, gliosis, and microglial activation. The temporal and frontal cortices showed additional patchy demyelination. T-lymphocyte infiltration was detectable in the fusiform gyrus lesion. These findings were partly similar to those reported in female patients. Although clinical differences based on the sex of the patient are reported for this disease, the observed pathological similarities potentially help to establish common therapeutic strategies for all patients. Severe testicular damage was additionally observed in the male patient in this study. Biopsy-proven severe testicular damage was also confirmed in another, previously fertile man who became azoospermic. Moreover, serum follicle-stimulating hormone levels, which often increased in response to disturbed spermatogenesis, were elevated, and testosterone/luteinizing hormone ratio reflecting Leydig cell function was low in all 5 male patients in this study. Overall, these findings suggest similar brain pathology in patients of both sexes and severe testicular damage in male patients.