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Background Intensive chemotherapeutic regimens with craniospinal irradiation have greatly improved survival in medulloblastoma patients. However, survival markedly differs among molecular subgroups and their biomarkers are unknown. Through unbiased screening, we found Schlafen family member 11 (SLFN11), which is known to improve response to DNA damaging agents in various cancers, to be one of the top prognostic markers in medulloblastomas. Hence, we explored the expression and functions of SLFN11 in medulloblastoma. Methods SLFN11 expression for each subgroup was assessed by immunohistochemistry in 98 medulloblastoma patient samples and by analyzing transcriptomic databases. We genetically or epigenetically modulated SLFN11 expression in medulloblastoma cell lines and determined cytotoxic response to the DNA damaging agents cisplatin and topoisomerase I inhibitor SN-38 in vitro and in vivo. Results High SLFN11 expressing cases exhibited significantly longer survival than low expressing cases. SLFN11 was highly expressed in the WNT-activated subgroup and in a proportion of the SHH-activated subgroup. While WNT activation was not a direct cause of the high expression of SLFN11, a specific hypomethylation locus on the SLFN11 promoter was significantly correlated with high SLFN11 expression. Overexpression or deletion of SLFN11 made medulloblastoma cells sensitive and resistant to cisplatin and SN-38, respectively. Pharmacological upregulation of SLFN11 by the brain-penetrant histone deacetylase-inhibitor RG2833 markedly increased sensitivity to cisplatin and SN-38 in SLFN11-negative medulloblastoma cells. Intracranial xenograft studies also showed marked sensitivity to cisplatin by SLFN11-overexpression in medulloblastoma cells. Conclusions High SLFN11 expression is one factor which renders favorable outcomes in WNT-activated and a subset of SHH-activated medulloblastoma possibly through enhancing response to cisplatin.

The neuropathological background of parkinsonism includes various neurodegenerative disorders, including Lewy body disease (LBD), multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD). The pathological diagnostic procedure begins by assessing the macroscopic findings to evaluate the degenerative lesions in brains with the naked eye. Usually, degenerative lesions show variable atrophy and brownish discoloration in accordance with disease-specific profiles. These macroscopic appearances support neuropathologists in identifying the relevant regions for microscopic examination. The neuropathological diagnosis of parkinsonism is based on regional distribution and fundamental proteinopathies in neurons and glia cells. LBD and MSA are synucleinopathies, and PSP and CBD are tauopathies. Among them, glial-predominant proteinopathy (MSA, PSP, and CBD) may play a significant role in volume reduction. Therefore, macroscopic inspection provides the appropriate direction for assessment. The disease duration, the severity of lesions, and mixed pathologies make the validation of macroscopic observations more complicated. In this review, we outline the macroscopic diagnostic clues in LBD, MSA, PSP, and CBD that could help with pathological refinement.

Progressive supranuclear palsy (PSP) can be diagnosed despite the presence of asymmetrical parkinsonism depending on the clinical diagnostic criteria. Some studies have reported that atrophy of the superior cerebellar peduncle (SCP) is more frequent in PSP than in Parkinson's disease. There have also been reports of PSP cases with an asymmetrically atrophic SCP. Therefore, we analyzed 48 specimens from consecutive autopsy cases that were neuropathologically diagnosed as PSP to investigate the laterality of brain lesions, including the SCP. We measured the width of the SCP and evaluated the laterality of atrophy. We semi-quantitatively evaluated neuronal loss, atrophy/myelin pallor, and tau pathology in three steps. Asymmetrical atrophy of the SCP was present in seven (14.6%) of 48 cases. The atrophic side of the SCP corresponded to the dominant side of the tau pathology in the cerebellar dentate nucleus. It was opposite to the dominant side of the myelin pallor and tau pathology in the red nucleus and of the tau pathology in the central tegmental tract and inferior olivary nucleus, coinciding with the neurologically systematic anatomy of the Guillain-Mollaret triangle. Neurodegeneration of PSP can progress asymmetrically from one side to the initially intact side in PSP with an initial predominance of Richardson's syndrome, progressive gait freezing, ocular motor dysfunction, parkinsonism, or corticobasal syndrome. To our knowledge, no previous study has reported asymmetrical PSP neuropathology; this is the first study to report the presence of PSP cases with asymmetrical SCP atrophy and systematically asymmetrical degeneration of the Guillain-Mollaret triangle.

The hot cross bun (HCB) sign encompasses a cross-shaped hyperintensity area in the pons on axial T2-weighted magnetic resonance imaging (MRI). The HCB sign is characteristic of multiple system atrophy (MSA) and has occasionally been observed in other neurological disorders. Here, we report an autopsied case of corticobasal degeneration (CBD) that showed the HCB sign. A female patient presented with progressive gait disturbance and cognitive impairment at the age of 60 years. A neurological examination revealed dysarthria, muscle rigidity of the limbs, akinesia, truncal ataxia, urinary incontinence, and dementia. The HCB sign was observed on a brain MRI at the age of 65 years, and a clinical diagnosis of possible MSA was made. She died of pneumonia at the age of 67 years. A postmortem observation, provided neuropathological findings characteristic of CBD, including the presence of astrocytic plaques, pretangles, neuropil threads, and ballooned neurons in association with four-repeat-tau aggregation. Interestingly, the pons displayed severe neuronal loss and astrogliosis that were prominent in the pontine and raphe nuclei. Myelin sheath depletion was prominent in the transverse fibers of the pontine base and the myelinated fibers of the pontine tegmentum in contrast to relative sparing of the pontine corticospinal tract and medial lemniscus. The cerebellar dentate nucleus exhibited neuronal loss and grumose degeneration. Western blot analysis of sarkosyl-insoluble fractions from brain tissue lysates using an anti-phosphorylated tau antibody identified immunoreactive signal bands in approximately 37-40, 43, 64, and 68 kDa, consistent with CBD. Genetic analysis did not reveal any known pathogenic mutations in the microtubule-associated protein tau gene (MAPT). Our case was characterized by the HCB sign and concordant neuropathological changes in the pons. CBD should be considered an underlying pathology of the HCB sign, even though the pontocerebellar changes would be unusual in CBD cases.

BACKGROUND Mutations in PRKN are the most common cause of autosomal recessive juvenile parkinsonism. The objective of this study was to investigate the association between genotype and pathology in patients with PRKN mutations. METHODS We performed a sequence and copy number variation analysis of PRKN, mRNA transcripts, Parkin protein expression, and neuropathology in 8 autopsied patients. RESULTS All the patients harbored biallelic PRKN mutations. Two patients were homozygous and heterozygous, respectively, for the missense mutation p.C431F. Seven patients had exon rearrangements, including 2 patients from a single family who harbored a homozygous deletion of exon 4, and 3 patients who carried a homozygous duplication of exons 6-7, a homozygous duplication of exons 10-11, and a heterozygous duplication of exons 2-4. In the other 2 patients, we found a compound heterozygous duplication of exon 2, deletion of exon 3, and a heterozygous duplication of exon 2. However, sequencing of cDNA prepared from mRNA revealed 2 different transcripts derived from triplication of exon 2 and deletion of exons 2-3 and from duplication of exons 2-4 and deletion of exons 3-4. Western blotting and immunohistochemistry revealed faint or no expression of Parkin in their brains. In the substantia nigra pars compacta, a subfield-specific pattern of neuronal loss and mild gliosis were evident. Lewy bodies were found in 3 patients. Peripheral sensory neuronopathy was a feature. CONCLUSIONS Genomic and mRNA analysis is needed to identify the PRKN mutations. Variable mutations may result in no or little production of mature Parkin and the histopathologic features may be similar. © 2021 International Parkinson and Movement Disorder Society.

Glioma-associated oncogene homolog 3 (GLI3), whose main function is to inhibit GLI1, has been associated with neuronal differentiation in medulloblastoma. However, it is not clear what molecular subtype(s) show increased GLI3 expression. GLI3 levels were assessed by immunohistochemistry in 2 independent cohorts, including a total of 88 cases, and found to be high in both WNT- and SHH-activated medulloblastoma. Analysis of bulk mRNA expression data and single cell RNA sequencing studies confirmed that GLI1 and GLI3 are highly expressed in SHH-activated medulloblastoma, whereas GLI3 but not GLI1 is highly expressed in WNT-activated medulloblastoma. Immunohistochemical analysis has shown that GLI3 is expressed inside the neuronal differentiated nodules of SHH-activated medulloblastoma, whereas GLI1/2 are expressed in desmoplastic areas. In contrast, GLI3 is diffusely expressed in WNT-activated medulloblastoma, whereas GLI1 is suppressed. Our data suggest that GLI3 may be a master regulator of neuronal differentiation and morphology in these subgroups.

Methionine/methionine type 1 (MM1-type) sporadic Creutzfeldt-Jakob disease (sCJD), known as the ‘classic type,’ shows typical clinicopathological sCJD findings. In general, patients reach an akinetic mutism state within a few months of disease onset and die soon after if supportive therapies are not administered. Here, we describe remarkable neuropathologic observations of MM1-type sCJD in a 48-year-old, Japanese man with an unusually prolonged akinetic mutism state. In the early disease stages, the patient exhibited abnormal behaviour with gait disturbance and rapidly progressive cognitive dysfunction. Diffusion-weighted magnetic resonance imaging revealed extensive cerebral cortical hyperintensity. Prion protein (PrP) gene analysis revealed no mutations, and the polymorphic codon 129 exhibited methionine homozygosity. Although the patient remained stable with tube feeding for more than 2 years after reaching the akinetic mutism state, he died because of central respiratory failure 30 months after disease onset. Neuropathologic investigation showed extensive devastating lesions, such as status spongiosus, and typical spongiform changes could no longer be observed in the cerebral neocortex. Conspicuous pyramidal tract degeneration was observed. However, the regions commonly preserved in MM1-type sCJD pathology were still relatively preserved. Immunostaining revealed extensive diffuse synaptic-type PrP deposition in the grey matter. The pathological findings suggested that sCJD is a neurodegenerative disease that shows system degeneration; there are primary and secondary degenerative regions and distinct preserved regions, even in cases with prolonged disease duration. In addition, it is considered that there is a limited survival period for MM1-type sCJD, even if active symptomatic treatment is provided.

Subacute sclerotic panencephalitis (SSPE) is a refractory neurological disorder after exposure to measles virus. Recently, SSPE cases have been treated with antiviral therapies, but data on the efficacy are inconclusive. Abnormal tau accumulation has been reported in the brain tissue of SSPE cases, but there are few reports in which this is amply discussed. Five autopsied cases diagnosed as definite SSPE were included in this study. The subject age or disease duration ranged from 7.6 to 40.9 years old or from 0.5 to 20.8 years, respectively. Cases 3 and 4 had been treated with antiviral therapies. All evaluated cases showed marked brain atrophy with cerebral ventricle dilatation; additionally, marked demyelination with fibrillary gliosis were observed in the cerebral white matter. The brainstem, cerebellum, and spinal cord were relatively preserved. Immunoreactivity (IR) against measles virus was seen in the brainstem tegmentum, neocortex, and/or limbic cortex of the untreated cases but was rarely seen in the two treated cases. Activated microglia were broadly observed from the cerebrum to the spinal cord and had no meaningful difference among cases. Neurofibrillary tangles characterized by a combination of 3- and 4-repeat tau were observed mainly in the oculomotor nuclei, locus coeruleus, and limbic cortex. IR against phosphorylated tau was seen mainly in the cingulate gyrus, oculomotor nuclei, and pontine tegmentum, and tended to be observed frequently in cases with long disease durations but also tended to decrease along with neuronal loss, as in Case 5, which had the longest disease duration. Since the distribution of phosphorylated tau was independent from that of measles virus, the tauopathy following SSPE was inferred to be the result of diffuse brain inflammation triggered by measles rather than a direct result of measles virus. Moreover, antiviral therapies seemed to suppress measles virus but not the progression of tauopathy.

We describe an autopsied patient with familial parkinsonism and unclassified four repeat-tau (4R-tau) aggregation. She presented with bradykinesia, truncal dystonia, and mild amnesia at the age of 61 and then exhibited body weight loss (15 kg over 8 months), sleep disturbances, and progressive respiratory failure with CO2 narcosis. She died of respiratory failure at the age of 62, 14 months after disease onset. Her brother also showed parkinsonism at the age of 58 and suddenly died 6 months later. Postmortem examination revealed 4R-tau aggregation, which was characterized by neuronal globose-type tangles or pretangles, bush-like or miscellaneous astrocytic inclusions, and coiled bodies. The temporal tip, the striatum, the substantia nigra, the tegmentum of the midbrain, the medullary reticular formation, and the spinal cord were severely involved with tau aggregation. Argyrophilic grains and ballooned neurons were also found in the medial temporal structures, however, extensions of the 4R-aggregations in the case were clearly broader than those of the argyrophilic grains. Western blot analysis of sarkosyl-insoluble fractions from brain lysates revealed prominent bands of tau at both 33 kDa and 37 kDa. Genetic examinations did not reveal any known pathogenic mutations in MAPT, DCTN-1, PSEN-1, or familial or young-onset parkinsonism-related genes. The clinical manifestations, pathologic findings, and biochemical properties of aggregated tau in our patient cannot be explained by argyrophilic grain disease or other known 4R-tauopathies alone. Our results further extend the clinical and neuropathologic spectra of 4R-tauopathy.

We report a case of early-phase sporadic Creutzfeldt-Jakob disease (sCJD) complicated by intracerebral hemorrhage (ICH), classified as MM1 + 2C-type based on autopsy. A 61-year-old Japanese man presented to our hospital with speaking difficulties including repeated usage of the same words. He was hospitalized on the seventh day after symptom onset, and diffusion-weighted images on magnetic resonance imaging showed hyperintense regions in the frontal cortex and caudate nucleus. On the 11th day after symptom onset, head computed tomography revealed ICH in the right occipital and parietal lobes. Routine laboratory evaluations and angiography revealed no cause of ICH. Myoclonus of the extremities and drowsiness were observed on the 15th day after symptom onset. He reached the state of akinetic mutism approximately two months after symptom onset. The cerebrospinal fluid test revealed positive real-time quaking-induced conversion and 14-3-3 protein. Electroencephalography revealed periodic sharp wave complexes. A clinical diagnosis of probable Creutzfeldt-Jakob disease was made according to the diagnostic criteria. After a relapse of pneumonia, he passed away on the 103rd day after symptom onset. Postmortem examination revealed ICH in the right posterior cingulate gyrus. No pathological change that might have caused ICH was obtained. Although the effect of sCJD on the onset of ICH is undeniable, the cause of ICH was unknown. Prion protein immunohistochemistry revealed the following results: (1) weak synaptic-type deposits in the tissue rarefacted by ICH; (2) synaptic-type deposits in the cerebral cortex, which showed fine vacuoles; and (3) perivacuolar-type deposits in the inferior temporal gyrus and lingual gyrus, which showed frequent large confluent vacuoles. Although it could be considered MM1-type sCJD clinically, this case was neuropathologically diagnosed as having MM1 + 2C-type sCJD. It was shown that ICH may occur in early-phase sCJD. To improve sCJD prognosis, treatment of complications and careful follow up are important. Furthermore, pathological diagnosis is indispensable for sCJD type diagnosis.

TDP-43 is mislocalized from the nucleus and aggregates within the cytoplasm of affected neurons in cases of amyotrophic lateral sclerosis. TDP-43 pathology has also been found in brain tissues under non-amyotrophic lateral sclerosis conditions, suggesting mechanistic links between TDP-43-related amyotrophic lateral sclerosis and various neurological disorders. This study aimed to assess TDP-43 pathology in the spinal cord motor neurons of tauopathies. We examined 106 spinal cords from consecutively autopsied cases with progressive supranuclear palsy (n = 26), corticobasal degeneration (n = 12), globular glial tauopathy (n = 5), Alzheimer’s disease (n = 21) or Pick's disease (n = 6) and neurologically healthy controls (n = 36). Ten of the progressive supranuclear palsy cases (38%) and seven of the corticobasal degeneration cases (58%) showed mislocalization and cytoplasmic aggregation of TDP-43 in spinal cord motor neurons, which was prominent in the cervical cord. TDP-43 aggregates were found to be skein-like, round-shaped, granular or dot-like and contained insoluble C-terminal fragments showing blotting pattern of amyotrophic lateral sclerosis or frontotemporal lobar degeneration. The lower motor neurons also showed cystatin-C aggregates, although Bunina bodies were absent in haematoxylin-eosin staining. The spinal cord TDP-43 pathology was often associated with TDP-43 pathology of the primary motor cortex. Positive correlations were shown between the severities of TDP-43 and four-repeat (4R)-tau aggregates in the cervical cord. TDP-43 and 4R-tau aggregates burdens positively correlated with microglial burden in anterior horn. TDP-43 pathology of spinal cord motor neuron did not develop in an age-dependent manner and was not found in the Alzheimer’s disease, Pick's disease, globular glial tauopathy and control groups. Next, we assessed SFPQ expression in spinal cord motor neurons; SFPQ is a recently identified regulator of amyotrophic lateral sclerosis/frontotemporal lobar degeneration pathogenesis, and it is also reported that interaction between SFPQ and FUS regulates splicing of MAPT exon 10. Immunofluorescent and proximity-ligation assays revealed altered SFPQ/FUS-interactions in the neuronal nuclei of progressive supranuclear palsy, corticobasal degeneration and amyotrophic lateral sclerosis-TDP cases but not in Alzheimer’s disease, Pick's disease and globular glial tauopathy cases. Moreover, SFPQ expression was depleted in neurons containing TDP-43 or 4R-tau aggregates of progressive supranuclear palsy and corticobasal degeneration cases. Our results indicate that progressive supranuclear palsy and corticobasal degeneration may have properties of systematic motor neuron TDP-43 proteinopathy, suggesting mechanistic links with amyotrophic lateral sclerosis-TDP. SFPQ dysfunction, arising from altered interaction with FUS, may be a candidate of the common pathway.

The liver function is essential for metabolism, detoxification, and bile synthesis, even in the neonatal period. Autophagy plays significance roles in THE adult liver, whereas the role of liver autophagy in the early neonatal period largely remains unclear. To clarify the importance of liver autophagy in the neonatal starvation period, we generated liver-specific autophagy-deficient (Atg5flox/flox, Albumin-Cre) mice and investigated under starvation conditions comparing with control (Atg5flox/+, Albumin-Cre) mice, focusing on serum metabolites and liver histopathology. As a result, autophagy in the liver was found to unessential for the survival under postnatal starvation. A metabolomics analysis of serum metabolites by gas chromatography-tandem mass spectrometry showed a significant difference between the groups, especially after 12-h starvation, suggesting the synergistical adaption of metabolic pathways, such as the “malate-aspartate shuttle”, “aspartate metabolism”, “urea cycle”, and “glycine and serine metabolism”. Liver-specific autophagy-deficiency under postnatal starvation conditions can cause a characteristic metabolic alteration suggesting a change of the mitochondrial function. Neonates seemed to maintain ketone production under starvation conditions, even in the autophagy-deficient liver, through a change in the mitochondrial function, which may be an adaptive mechanism for avoiding fatal starvation.

Comprehensive analysis is required for the accurate diagnosis of MV2-type sporadic Creutzfeldt-Jakob disease (sCJD) because it shows a wide clinicopathological spectrum. Here, we describe the clinical findings and neuropathologic observations of an autopsy-confirmed MV2K-type sCJD case with extensive spongiform changes of the cerebral cortex. In the early disease stages, the patient exhibited gait disturbance with ataxia and gradually showed cognitive dysfunction. Diffusion-weighted magnetic resonance images revealed hyperintense regions in the cerebral cortex, basal ganglia, and particularly in the thalamus. Prion protein (PrP) gene analysis revealed no mutations, and polymorphic codon 129 exhibited methionine and valine heterozygosity. During the course of the disease, a startle reaction was observed, whereas myoclonus was not observed. Electroencephalography showed no periodic sharp wave complexes. The patient died at age 61 years with 13 months total disease duration and did not reach the akinetic mutism state. Pathologic investigation revealed extensive fine vacuole-type spongiform change in the cerebral cortex, and the appearance of vacuolation tended to be more pronounced in the deeper layers. Numerous kuru plaques were observed in the cerebellum. PrP immunostaining revealed extensive diffuse synaptic-type PrP deposition in the cerebral cortex, and the finding was prominent in the deeper layer with perineuronal-type PrP deposition. In the limbic system, basal ganglia, and thalamus, mixed small plaque-type PrP with synaptic-type PrP deposition was observed. In the cerebellar cortex, diffuse synaptic-type PrP depositions were observed with numerous strongly immunopositive plaques. Western blot analysis of examined brain samples revealed mixed type 2 PrPSc (scrapie type) and intermediate-type PrPSc .

We present an autopsied case with A8344G-mutated myoclonus epilepsy with ragged red fibers (MERRF)/mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) overlap syndrome accompanied by stroke-like episodes localized to the precentral gyrus. A 16-year-old Japanese woman suddenly experienced repetitive consciousness disturbances with increased serum lactate and creatine kinase levels. Magnetic resonance imaging showed abnormal intensity of bilateral precentral gyrus. She was clinically diagnosed as having a mitochondrial disorder and the A8344G mutation was detected in mitochondrial DNA. At 17 years of age, she died from congestive heart failure secondary to a third episode of lactic acidosis. Neuropatho-logically, multifocal laminar necrosis, which is responsible for stroke-like episodes in MELAS, was seen in the frontal cortex including the precentral gyrus, but there was no neuronal loss and gliosis in the basal ganglia, cerebellum, and brainstem, which were compatible with MERRF. Hypertrophy of the vascular smooth muscle and choroidal epithelium were seen, and were strongly visualized by an anti-mitochondrial antibody. Skeletal muscles showed uneven muscular diameters, increased central nuclei, and ragged red fibers (RRFs). Decreased cytochrome c oxidase (COX) activity and strongly succinate dehydrogenase (SDH)-reactive blood vessels were also noted. Stroke-like episodes in MERRF/MELAS overlap syndrome are thought to be rare in the frontal cortex including the precentral gyrus. Only two cases of MERRF/MELAS overlap syndrome with A8344G mutation, including this case, have shown stroke-like episodes in the frontal lobes. Other than the A8344G mutation and frontal lobe involvement, they had a high degree of similarity in terms of presence of RRFs, gastrointestinal dysfunction, and lack of typical MERRF neuropathology. In conclusion, this is an important case describing the clinical spectrum associated with A8344G-mutated MERRF/MELAS overlap syndrome.

MYC amplification is common in Group 3 medulloblastoma and is associated with poor survival. Group 3 and Group 4 medulloblastomas are also known to have elevated levels of histone H3-lysine 27-tri-methylation (H3K27me3), at least in part due to high expression of the H3K27 methyltransferase enhancer of zest homologue 2 (EZH2), which can be regulated by MYC. We therefore examined whether MYC expression is associated with elevated EZH2 and H3K27me3 in medulloblastoma, and if high-MYC medulloblastomas are particularly sensitive to pharmacological EZH2 blockade. Western blot analysis of low (DAOY, UW228, CB SV40) and high (DAOY-MYC, UW228-MYC, CB-MYC, D425) MYC cell lines showed that higher levels of EZH2 and H3K27me3 were associated with elevated MYC. In fixed medulloblastoma samples examined using immunohistochemistry, most MYC positive tumors also had high H3K27me3, but many MYC negative ones did as well, and the correlation was not statistically significant. All high MYC lines tested were sensitive to the EZH2 inhibitor EPZ6438. Many low MYC lines also grew more slowly in the presence of EPZ6438, although DAOY-MYC cells responded more strongly than parent DAOY cultures with lower MYC levels. We find that higher MYC levels are associated with increased EZH2, and pharmacological blockade of EZH2 is a potential therapeutic strategy for aggressive medulloblastoma with elevated MYC.

Summary Neuronal intranuclear inclusion disease (NIID) is a neurodegenerative disease characterized by the presence of intranuclear inclusions of unknown origin. NIID is caused by an expansion of GGC repeats in the 5′ UTR of the NOTCH2NLC (N2C) gene. We found that these repeats are embedded in a small upstream open reading frame (uORF) (uN2C), resulting in their translation into a polyglycine-containing protein, uN2CpolyG. This protein accumulates in intranuclear inclusions in cell and mouse models and in tissue samples of individuals with NIID. Furthermore, expression of uN2CpolyG in mice leads to locomotor alterations, neuronal cell loss, and premature death of the animals. These results suggest that translation of expanded GGC repeats into a novel and pathogenic polyglycine-containing protein underlies the presence of intranuclear inclusions and neurodegeneration in NIID., Graphical abstract, Highlights • NIID is a neurodegenerative disease caused by expansion of GGC repeats in NOTCH2NLC • These GGC repeats are translated into a polyglycine (polyG) protein • The polyG protein is toxic and forms intranuclear inclusions in cells and animals • Similarities between FXTAS and NIID define a new set of disorders: polyG diseases, The neurodegenerative disease NIID is caused by an expansion of GGC repeats in NOTCH2NLC. Boivin et al. found that these repeats are translated into a toxic polyglycine (polyG) protein that forms intranuclear inclusions. An identical mechanism exists in FXTAS, unveiling a novel group of genetic pathologies, the polyG diseases.

Leucyl-tRNA synthetase (LARS) is an enzyme that catalyses the ligation of leucine with leucine tRNA. LARS is also essential to sensitize the intracellular leucine concentration to the mammalian target of rapamycin complex 1 (mTORC1) activation. Biallelic mutation in the LARS gene causes infantile liver failure syndrome type 1 (ILFS1), which is characterized by acute liver failure, anaemia, and neurological disorders, including microcephaly and seizures. However, the molecular mechanism underlying ILFS1 under LARS deficiency has been elusive. Here, we generated Lars deficient (larsb−/−) zebrafish that showed progressive liver failure and anaemia, resulting in early lethality within 12 days post fertilization. The atg5-morpholino knockdown and bafilomycin treatment partially improved the size of the liver and survival rate in larsb−/− zebrafish. These findings indicate the involvement of autophagy in the pathogenesis of larsb−/− zebrafish. Indeed, excessive autophagy activation was observed in larsb−/− zebrafish. Therefore, our data clarify a mechanistic link between LARS and autophagy in vivo. Furthermore, autophagy regulation by LARS could lead to development of new therapeutics for IFLS1.

Leucyl-tRNA synthetase (LARS) is an enzyme that catalyses the ligation of leucine with leucine tRNA. LARS is also essential to sensitize the intracellular leucine concentration to the mammalian target of rapamycin complex 1 (mTORC1) activation. Biallelic mutation in the LARS gene causes infantile liver failure syndrome type 1 (ILFS1), which is characterized by acute liver failure, anaemia, and neurological disorders, including microcephaly and seizures. However, the molecular mechanism underlying ILFS1 under LARS deficiency has been elusive. Here, we generated Lars deficient (larsb-/-) zebrafish that showed progressive liver failure and anaemia, resulting in early lethality within 12 days post fertilization. The atg5-morpholino knockdown and bafilomycin treatment partially improved the size of the liver and survival rate in larsb-/- zebrafish. These findings indicate the involvement of autophagy in the pathogenesis of larsb-/- zebrafish. Indeed, excessive autophagy activation was observed in larsb-/- zebrafish. Therefore, our data clarify a mechanistic link between LARS and autophagy in vivo. Furthermore, autophagy regulation by LARS could lead to development of new therapeutics for IFLS1.

We previously reported observing GLI3 in medulloblastomas expressing neuronal markers (NM) and/or glial fibrillary acidic protein (GFAP). Furthermore, patients with medulloblastomas expressing NM or GFAP tended to show favorable or poor prognosis, respectively. In the present study, we focused on the role of topoisomerase IIβ (TOP2β) as a possible regulator for neuronal differentiation in medulloblastomas and examined the pathological roles of GLI3, NM, GFAP, and TOP2β expressions in a larger population. We divided 124 medulloblastomas into three groups (NM−/GFAP−, NM +/GFAP−, and GFAP +) based on their immunoreactivity (IR) against NM and GFAP. The relationship among GLI3, NM, GFAP, and TOP2β was evaluated using fluorescent immunostaining and a publicly available single-cell RNA sequencing dataset. In total, 87, 30, and 7 medulloblastomas were classified as NM−/GFAP−, NM + /GFAP−, and GFAP +, and showed intermediate, good, and poor prognoses, respectively. GLI3-IR was frequently observed in NM +/GFAP− and GFAP + , and TOP2β-IR was frequently observed only in NM +/GFAP− medulloblastomas. In fluorescent immunostaining, TOP2β-IR was mostly co-localized with NeuN-IR but not with GFAP-IR. In single-cell RNA sequencing, TOP2β expression was elevated in CMAS/DCX-positive, but not in GFAP-positive, cells. NM-IR and GFAP-IR are important for estimating the prognosis of patients with medulloblastoma; hence they should be assessed in clinical practice.

To assess the induction of autophagy in the human umbilical cord for physiological adaptation against starvation.The expression of autophagy-related proteins (LC3-II, p62) in umbilical cord tissues from 40 neonates was assessed by Western blotting. The correlation between the expression of autophagy-related proteins and maternal findings (height, weight, body mass index [BMI]), placental weight, neonatal findings (gestational age, height, weight, Apgar score at 1 min and 5 min), and the pH of the umbilical arterial blood were analyzed using Spearman's rank correlation coefficient test (The expression of LC3-II was positively correlated with serum total protein (The LC3-II or p62 expression in the umbilical cord may suggest the autophagy reaction for the homeostasis of protein or amino acid metabolism in the perinatal period.

An 83-year-old Japanese man presented with gait disturbance followed by rapidly-progressive cognitive impairment. Magnetic resonance diffusion-weighted images showed extensive hyperintense regions in the cerebral cortex. Four weeks after symptom onset, myoclonus appeared, and the patient developed difficulty swallowing; intravenous peripheral continuous infusions without vitamin supplementation were administered during the last two months of the patient’s life. The patient reached the akinetic mutism state and died 12 weeks after symptom onset due to sepsis. The brain weighed 940 g and showed general cerebral atrophy. Extensive spongiform change were observed in the cerebral cortex, striatum, thalamus, and cerebellar cortex, but gliosis was generally mild. Numerous newly-developed hemorrhage foci were observed in the mammillary body, the areas adjacent to the third and fourth ventricles, and the periaqueduct of the midbrain; however, proliferation of capillaries and endothelium and collections of macrophages were relatively inconspicuous. These findings suggested comorbidity with the acute stage of Wernicke encephalopathy (WE). Immunostaining showed extensive diffuse synaptic-type prion protein deposition in the gray matter. According to the neuropathological, genetic, and molecular findings, the present case was finally diagnosed as MM1-type sporadic Creutzfeldt-Jakob disease (CJD) with WE. We should remain alert to the diagnosis of WE when CJD is suspected, and it is necessary to consider the complications of both diseases. This report emphasizes the importance of pathological investigations for the diagnosis of CJD, WE, and the coexistence of both.

A Japanese woman showed slowly progressive memory disturbance starting at the age of 84 years, and disorientation gradually appeared. Head computed tomography revealed severe hippocampal atrophy, whereas the atrophy of the frontal lobe was considerably mild for her age. Behavioral and psychological symptoms of dementia were relatively inconspicuous during the disease course. Apolipoprotein E gene analysis showed e3/e4 heterozygosity. She died at the age of 100 years and she was clinically diagnosed as having Alzheimer's disease (AD). Autopsy revealed numerous neurofibrillary tangles, particularly in the hippocampal region, and extensively distributed senile plaques in the brain. Although the findings were compatible with the pathological criteria for AD, combined pathologies of hippocampal sclerosis, trans-activation response DNA-binding protein 43 kDa, and α-synuclein were also revealed. We believe that the clinicopathological findings of the present case are of significance for the diagnosis of elderly dementia and pathogenesis of AD.

The patient was a Japanese woman who experienced a decrease in activity and gait disturbance as the initial symptoms at the age of 86, followed by disorientation and memory dysfunction. Magnetic resonance imaging showed extensive cortical regions with hyperintensity in diffusion-weighted images, and these regions showed swelling in T2-weighted and fluid-attenuated inversion recovery (FLAIR) images. The medial occipital cortex and striatum showed no apparent hyperintensity on diffusion-weighted imaging (DWI). Mild myoclonus was detected, and the patient died 10 months after the onset of symptoms; she did not enter the akinetic mutism state. The patient's brain weighed 1050 g, and neuropathological examination showed extensive characteristic various-sized and non-confluent (VaSNoC) vacuoles in the cerebral cortex. These vacuoles were observable macroscopically by loupe on images of hematoxylin and eosin-stained tissue. Gliosis, hypertrophic astrocytosis, and neuron loss were generally mild in character. Prion protein (PrP) immunostaining showed very mild diffuse-synaptic-type PrP deposition in the cerebral gray matter. These clinicopathological findings led us to several conclusions relative to the early disease pathology of V180I genetic Creutzfeldt-Jakob disease: (i) spongiform change was not found in the medial occipital cortex, which corresponds to the results of DWI; (ii) VaSNoC-type spongiform changes, extensively recognized in the cerebral cortex, corresponded to the DWI findings showing continued hyperintensity with higher brightness, and T2-weighted and FLAIR images findings showing a swelling; and (iii) spongiform changes first appear in the deeper layer and subsequently in the superficial layer in the cerebral cortex.

We present an autopsied case of non-plaque-type dura mater graft-associated Creutzfeldt-Jakob disease (dCJD) with extensive amyloid-β (Aβ) deposition in the brain. A 39-year-old Japanese woman presented with memory disturbance and abnormal behavior. The patient had a history of craniotomy with dura matter-graft transplant for a head injury which occurred when she was 19 years old. Magnetic resonance imaging (MRI) showed hyperintensities in the cerebral cortex and striatum on diffusion-weighted images, particularly on the dura mater-grafted right side. Her clinical symptoms, including rapidly progressing cognitive impairment, myoclonus, and periodic sharp wave complexes on electroencephalogram, could not be distinguished from typical sporadic CJD cases. The patient died 11 months after symptom onset, and pathological investigations showed extensive spongiform degeneration with prion protein (PrP) deposition without Kuru plaques; these observations were essentially the same as those of typical sporadic CJD cases. Furthermore, Aβ immunohistochemistry showed extensive diffuse staining in the cerebral neocortex, plaque-type deposition, positive staining in the pia mater, and cerebral amyloid angiopathy. Although the MRI findings suggested that the pathological involvement originated from the dura mater-grafted right side, the PrP and Aβ depositions showed no apparent regionalization and laterality. Tau-pathology including neurofibrillary tangles was hardly identified. The proteins phosphorylated α-synuclein and phosphorylated transactivation response DNA-binding protein 43 kDa were not detected on immunostaining. Although this report describes only one case, various speculations were made based on detailed clinical and pathological observations in conjunction with previous reports of dCJD. In particular, this report provides significant insight into the characteristics and progression of dCJD pathology and its relationship with Aβ pathology.

Human herpes virus 6 (HHV-6) is known to cause primary encephalitis in the frontal lobes/cerebral hemisphere or reactivated encephalitis in the hippocampus, but the pathogenesis remains unclear. HHV-6B has also been detected in hippocampal samples in patients with mesial temporal lobe epilepsy. A 1 year and 3 months old female, who had been clinically diagnosed with exanthema subitum and febrile convulsion, was found dead on the third day after onset. Macroscopic findings showed massive brain edema. Microscopic examination revealed gemistocytic astrocytes and ballooned oligodendrocytes in the frontal white matter, along with neuronal cell death with microglial infiltration in the frontal cortex. Polymerase chain reaction detected HHV-6B in the cerebrospinal fluid and necropsy brain samples. The hippocampus showed a 4-5-fold increase in virus copy number of HHV-6B compared to samples from other brain sites. Immunostaining indicated that HHV-6B had infected vascular endothelial cells, neurons and oligodendrocytes but not astrocytes or microglia. Hippocampal neurons were infected with highly concentrated HHV-6B, but the hippocampus had neither neuronal loss nor reactive glial response. Silent and abundant HHV-6B infection in the hippocampus might be associated with latent infection, reactivation and some hippocampus-oriented disorders, including mesial temporal lobe epilepsy.

Cerebral infarction in children is rare and often occurs secondary to moyamoya disease, hereditary coagulopathies, vasculitis, antiphospholipid antibody syndrome, heart disease, mitochondrial disease. However, in some cases, the causes of cerebral infarction is unknown. In this study, we detected increased levels of serum anti-phosphatidylcholine and anti-phosphatidylethanolamine IgG antibodies in three pediatric patients with cerebral infarction whose primary disorders are unknown by routine examination. For the five disease control patients of cerebral infarction due to other primary disorders, there was no such increase in these antibodies levels. Phosphatidylcholine and phosphatidylethanolamine are major components of the phospholipids of vascular endothelial cells, while cardiolipin is a minor component. Anti-phosphatidylcholine and anti-phosphatidylethanolamine antibodies, as well as anti-cardiolipin antibody, might also be risk factors with cerebral infarction.

Objective To elucidate the novel biological functions of heparan sulfate (HS) by clinic-pathologically studying a patient with paroxysmal atrioventricular (AV) block. Patient A long-surviving male patient with Sanfilippo syndrome type A presented with paroxysmal AV block at age 33 years. He then survived another 2.5 years after the onset of paroxysmal AV block and pacemaker implantation. Methods and results His cardiac histopathological examination at autopsy showed HS storage in the cardiac conduction system (CCS), especially in the atrioventricular node (AVN)-His bundle branches. Conclusion HS storage in the CCS might trigger AV block, arising from below the AVN-His bundle branches. This is the first description to indicate that HS might be an essential constituent of life-long CCS plasticity and that its storage in the CCS results in AV block.

BACKGROUND We have previously investigated the expression of Gli3, a downstream target of the Sonic Hedgehog pathway, which main function is to suppress Gli1/2 in medulloblastomas. We found that Gli3 is associated with neuronal and glial differentiation in desmoplastic / nodular (D/N) type medulloblastomas (Miyahara et al., Neuropathology, 2013). In the present study, we investigated the expression of Gli3 in molecular subgroups. METHOD Thirty-one medulloblastomas treated at Niigata University between 1982 and 2013 were studied. Molecular classification into 4 subgroups (WNT-activated, SHH-activated, Group 3 and Group 4) using Nanostring and immunohistochemistry was performed. Furthermore, Gli3 and Gli1 expression in molecular subgroups was assessed using public data bases. RESULTS Nanostring was considered reliable (confidence > 0.9) in 28 cases. Four cases were classified as WNT-, 5 cases as SHH-activated, 4 cases as Group 3 and 16 cases as Group 4. Gli3 was positive in 7 out of 9 (78%) WNT-/SHH- cases, but positive in only 8 out of 19 (42.1%) non-WNT-/SHH- subgroup cases (p = 0.1145, Fisher’s exact test). R2 database analysis confirmed that Gli3 was significantly elevated in WNT- and SHH-activated medulloblastoma. Gli1 was elevated in SHH-activated cases but suppressed in WNT-activated cases. IHC analysis revealed that Gli3 was elevated inside nodules showing neuronal differentiation in D/N type medulloblastoma. Results of single cell RNA analyses were consistent with those of IHC, Nanostring and R2. CONCLUSION These results suggest that Gli3 is elevated inside the nodules of SHH-activated medulloblastoma, whereas in WNT-activated cases, Gli3 diffusely suppresses HH signaling.

22q13 deletion syndrome is a genetic disorder caused by the deletion or disruption of the segment of the long arm of chromosome 22. The characteristic clinical features of this syndrome include delayed expressive speech, autistic behavior and hypotonia, and clinically severe complications associated with autoimmunity are rarely reported. We herein report a girl with 22q13 deletion syndrome complicated with multiple inflammatory and autoimmune diseases during early childhood. We performed whole-exome sequencing to identify the genes responsible for her autoimmune diseases and identified the de novo variant p.R512W in the phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit delta (PIK3CD) gene. We suspected it to be the disease-causing variant at the conserved residue in PIK(3)C p110δ. Alternatively, haplo-insufficiency of SHANK3 or other genes by 22q13 deletion and the PIK3CD variant might have synergistically contributed to the onset of the distinctive clinical manifestations in this patient.

The existence of affected subjects with both abnormal prion protein (PrPSc) types has been reported, and their clinical features were somewhat similar to the dominant PrPSc type but varied in sporadic Creutzfeldt-Jakob disease (sCJD). Presently, the antemortem identification of both PrPSc types in sCJD is not possible. In this study, we attempted to clinically predict the concurrence of MM-type sCJD with another PrPSc type in the same individual. We retrospectively identified seven MM-type sCJD cases with both fine vacuole-type spongiform (FV) and large confluent vacuole-type spongiform change (LCV) among 49 sCJD cases. We reviewed clinical features, pathological findings, and radiological abnormalities in these seven cases. We also conducted a regional systemic study with five brains to associate the spongiform-change pattern with hyperintensity on magnetic resonance diffusion-weighted imaging (DWI) using the signal intensity index (SII). In the case series study, the one patient with dominant LCV showed longer disease duration, later onset of typical symptoms, no periodic sharp wave complexes in electroencephalography, and negative 14-3-3 protein findings compared to the six FV-dominant patients. LCV-dominant lesions tended to show higher intensity on DWI than did the FV-dominant lesions in respective patients. In the regional systemic study, LCV-dominant regions showed significantly higher SII on DWI than did the FV-dominant regions. In conclusion, mixed MM-type sCJD generally showed the clinical features of the phenotype that was dominant in pathological distribution. The SII may be clinically useful for investigating the concurrence of PrPSc type 2 in cases with the typical clinical course of MM1-type sCJD.

We encountered an autopsy case of sporadic Creutzfeldt-Jakob disease (CJD) pathologically classified as MM1+2C-type, where Western blot analysis of prion protein (PrP) mainly showed type-1 scrapie PrP (PrPSc ) but also, partially, mixed type-2 PrPSc . A Japanese woman complained of visual disorder at the age of 86 years and then showed disorientation and memory disturbances. Magnetic resonance imaging (MRI) showed cerebral cortical hyperintensity on diffusion-weighted images. The patient died 2 months after the onset of symptoms; her condition did not reach the akinetic mutism state and periodic sharp-wave complexes on electroencephalography and myoclonus were not recognized. The brain weighed 1100 g and neuropathological examination showed extensive fine vacuole-type spongiform changes in the cerebral cortex. In some cortical regions, large confluent vacuole-type spongiform changes were also present. Gliosis and hypertrophic astrocytosis were generally mild, and tissue rarefaction of the neuropil and neuronal loss were not apparent. PrP immunostaining showed diffuse synaptic-type PrP deposition in the cerebral gray matter, but some regions with large confluent vacuoles showed perivacuolar-type deposition. We speculated, based on the clinicopathological findings and previous reports, that most MM1-type sporadic CJD cases may be associated with type-2 PrPSc , at least partially, within certain regions of the cerebrum.

BACKGROUND We previously reported that Gli3, which was a downstream molecule of Sonic Hedgehog signal, induced neuronal and/or glial differentiation in some types of medulloblastoma (desmoplastic/nodular medulloblastoma and medulloblastoma with extensive nodularity), and patients of medulloblastoma with neuronal differentiation showed favorable prognosis, but those with glial differentiation tended to show miserable prognosis (Miyahara H, Neuropathology, 2013). This time, we focused on Topoisomerase II β (Top2β), which was reported to induce neuronal differentiation and inhibit glial differentiation, and examined the expression of Top2β in medulloblastomas with neuronal and glial differentiations. METHODS We assessed the expression of Top2β, NeuN, and GFAP using triple fluorescent immunostaining method in medulloblastoma samples with both neuronal and glial differentiations. Furthermore, the expression of Top2β, H3K4me2, and H3K27me3 were also assessed, because Top2βwas positively or negatively regulated by H3K4me2 and H3K27me3, respectively. RESULTS Many large nuclei in the nodules, in which differentiated cells were seen, was visualized by Top2β. The Top2β signals were seen in NeuN+ cells but not GFAP+ cells. H3K4me2 signals were visualized in Top2β+ large nuclei, but H3K27me3 and NeuN+ large nuclei were distributed independently. CONCLUSIONS These results indicate that Top2β may be a molecule associated with neuronal, but not glial, differentiation of medulloblastoma cells. Drugs targeting histone modification enzymes such as EZH2 inhibitors are possible therapeutic targets as a differentiation-inducing therapy for medulloblastoma.

Rathke's cleft cysts (RCCs) are non-neoplastic, sellar or suprasellar epithelium-lined cysts originating from Rathke's pouch in the pituitary gland. Patients with RCCs are usually asymptomatic, but some have only been identified when symptoms manifested in middle age. The characteristics of these patients during childhood or adolescence remains unknown. We describe an 18-year-old girl who had occasionally suffered from malicious fatigue in the morning since her early teens. Brain magnetic resonance imaging (MRI) revealed T1 hyperintense/T2 hypointense signals between the anterior and posterior pituitary glands, indicating the presence of RCC. Based on an authentic endocrinological evaluation, her adrenal function seemed normal; nevertheless, her serum cortisol level strangely dropped around noon. Furthermore, daily supplementation of oral hydrocortisone bizarrely suppressed ACTH secretion to below the detection range in the morning. These data appeared compatible with the presence of central adrenal dysfunction. We also review the literature for previously reported cases. In conclusion, the symptoms and endocrinological data for dysfunction of the hypothalamic pituitary system might be non-specific and vary among patients, especially in teenagers. Brain MRI and daily cortisol profiling in blood are key to obtaining a diagnosis of an impaired hypothalamic adrenal function due to RCC.

Diffuse intrinsic pontine glioma (DIPG) is an invasive and treatment-refractory pediatric brain tumor. Primary DIPG tumors harbor a number of mutations including alterations in PTEN, AKT, and PI3K and exhibit activation of mammalian Target of Rapamycin Complex 1 and 2 (mTORC1/2). mTORC1/2 regulate protein translation, cell growth, survival, invasion, and metabolism. Pharmacological inhibition of mTORC1 is minimally effective in DIPG. However, the activity of dual TORC kinase inhibitors has not been examined in this tumor type. Nanomolar levels of the mTORC1/2 inhibitor TAK228 reduced expression of p-AKTS473 and p-S6S240/244 and suppressed the growth of DIPG lines JHH-DIPG1, SF7761, and SU-DIPG-XIII. TAK228 induced apoptosis in DIPG cells and cooperated with radiation to further block proliferation and enhance apoptosis. TAK228 monotherapy inhibited the tumorigenicity of a murine orthotopic model of DIPG, more than doubling median survival (p = 0.0017) versus vehicle. We conclude that dual mTOR inhibition is a promising potential candidate for DIPG treatment.

Cockayne syndrome presents senescence-like changes starting in early infancy; however, the mechanism of premature aging remains unclear. In an autopsy of a 23-year-old woman with Cockayne syndrome, we evaluated the correlation between Cockayne pathology and the expression patterns of the senescence-associated proteins p53 and Rb. Neuropathological findings in this case revealed basal ganglia calcification, tigroid leukodystrophy, bizarre reactive astrocytes, severe cerebellar atrophy with loss of Purkinje cells, and arteriolar/neuronal calcifications in the hypothalamus. Multiple arteriolar calcifications and sclerotic changes were seen in the central nervous system and kidney, but the endothelium of the aorta and coronary arteries remained intact appropriately for the individual's age without any finding of arteriosclerosis. Overexpression of p53 protein was confirmed in the cytoplasm of neurons in the basal ganglia, thalamus, hypothalamus, hippocampus and cerebellum, of arteriolar endothelial cells of the cerebrum and renal glomerular capillaries, and of cutaneous epithelial cells. The distribution of p53 overexpression was coincident with that of pathological alteration, such as neuronal loss, calcification and atrophy. High expression of p53 was localized in the cytoplasm, not in the nucleus. In contrast to p53, Rb was not expressed in any senescence lesion. In terms of senescence, distinct differences are found among organs in a patient with Cockayne syndrome. This segmental progeria differs from natural aging, and implicates p53 overexpression in the etiology of CS.

BACKGROUND: We have previously investigated the expression of Gli3, a downstream target of the Sonic Hedgehog pathway, which main function is to suppress Gli1/2 in medulloblastomas. We found that Gli3 is associated with neuronal and glial differentiation in desmoplastic / nodular (D/N) type medulloblastomas (Miyahara et al., Neuropathology, 2013). In the present study, we investigated the expression of Gli3 in the molecular subgroups. METHOD: Thirty-one medulloblastomas treated at Department of Neurosurgery, Niigata University between 1982 and 2013 were retrospectively studied. Molecular classification into 4 subgroups (WNT-activated, SHH-activated, Group 3 and Group 4) was performed using Nanostring. HE and NeuN, GFAP, beta-catenin, GAB-1, and YAP-1 immunohistochemistry was performed. Furthermore, Gli3 and Gli1 expression in each molecular subgroup was assessed in the public data base R2. RESULTS: Nanostring was considered reliable (confidence > 0.9) in 28 cases. Four cases were classified as WNT- activated, 5 cases as SHH-activated, 4 cases as Group 3 and 16 cases as Group 4. Gli3 was positive in 7 out of 9 (78%) WNT-/SHH- cases, whereas Gli3 was positive in only 8 out of 19 (42.1%) non-WNT-/SHH- subgroup (p = 0.1145, Fishers exact test). R2 database analysis confirmed that Gli3 was significantly elevated in WNT- and SHH-activated medulloblastoma. Gli1 was elevated in SHH-activated cases but suppressed in WNT-activated cases. IHC analysis revealed that Gli3 was elevated inside the nodules of D/N type medulloblastoma. Neuronal differentiation was seen in these nodules. CONCLUSION: These results suggest that Gli3 is elevated inside the nodules of SHH-activated medulloblastoma, whereas in WNT-activated cases, Gli3 suppresses HH signaling in the entire tumor.

Medulloblastoma (MB) is a malignant cerebellar tumor arising in children,and its ontogenesis is regulated by Sonic Hedgehog (Shh) signaling. No data are available regarding the correlation between expression of Gli3, a protein lying downstream of Shh, and neuronal differentiation of MB cells, or the prognostic significance of these features. We re-evaluated the histopathological features of surgical specimens of MB taken from 32 patients, and defined 15 of them as MB with neuronal differentiation (ND), three as MB with both glial and neuronal differentiation (GD), and 14 as differentiation-free (DF) MB.Gli3-immunoreactivity (IR) was evident as a clear circular stain outlining the nuclei of the tumor cells.The difference in the frequency of IR between the ND+GD (94.4%) and DF (0%) groups was significant (P < 0.001). The tumor cells with ND showed IR for both Gli3 and neuronal nuclei. Ultrastructurally, Gli3-IR was observed at the nuclear membrane. The overall survival and event-free survival rates of the patients in the ND group were significantly higher than those in the other groups. The expression profile of Gli3 is of considerable significance, and the association of ND with this feature may be prognostically favorable in patients with MB.