Yuu Yamazaki

Immunopositivity for ESCRT-III subunit CHMP2B in granulovacuolar degeneration of neurons in the Alzheimer's disease hippocampus

Endosomal sorting complex required for transport (ESCRT)-III subunit charged multivesicular body protein 2B (CHMP2B) is involved in the degradation of proteins in the endocytic and autophagic pathways. Mutations in the CHMP2B gene are reportedly associated with frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) characterised by accumulation of ubiquitinated protein aggregates in affected neurons, suggesting a relationship between protein accumulation and efficient autophagic degradation. This study investigated CHMP2B immunoreactivity in the hippocampus of patients with Alzheimers disease (AD), revealing intense labeling of intraneuronal dot-like structures by antibody to CHMP2B. Since the morphological characteristics of these granular structures were compatible with those of granulovacuolar degeneration (GVD), a hallmark of AD pathology, immunohistochemical study using anti-CHMP2B antibody was performed using AD and control brain sections to investigate whether this antibody can be used as a GVD label. The number and percentage of hippocampal neurons with CHMP2B-positive granules were higher in AD cases and CHMP2B-positive granules corresponded to GVD. Anti-CHMP2B antibody detected a single 28-kDa band on Western blotting using control and AD specimens. This antibody clearly and intensely detected GVD over the hippocampus and entorhinal and transentorhinal cortices. These findings suggest that researchers will be able to use CHMP2B as a molecular label for studying GVD.

Granulovacuolar Degenerations Appear in Relation to Hippocampal Phosphorylated Tau Accumulation in Various Neurodegenerative Disorders

Background Granulovacuolar degeneration (GVD) is one of the pathological hallmarks of Alzheimers disease (AD), and it is defined as electron-dense granules within double membrane-bound cytoplasmic vacuoles. Several lines of evidence have suggested that GVDs appear within hippocampal pyramidal neurons in AD when phosphorylated tau begins to aggregate into early-stage neurofibrillary tangles. The aim of this study is to investigate the association of GVDs with phosphorylated tau pathology to determine whether GVDs and phosphorylated tau coexist among different non-AD neurodegenerative disorders. Methods An autopsied series of 28 patients with a variety of neurodegenerative disorders and 9 control patients were evaluated. Standard histological stains along with immunohistochemistry using protein markers for GVD and confocal microscopy were utilized. Results The number of neurons with GVDs significantly increased with the level of phosphorylated tau accumulation in the hippocampal regions in non-AD neurodegenerative disorders. At the cellular level, diffuse staining for phosphorylated tau was detected in neurons with GVDs. Conclusions Our data suggest that GVDs appear in relation to hippocampal phosphorylated tau accumulation in various neurodegenerative disorders, while the presence of phosphorylated tau in GVD-harbouring neurons in non-AD neurodegenerative disorders was indistinguishable from age-related accumulation of phosphorylated tau. Although GVDs in non-AD neurodegenerative disorders have not been studied thoroughly, our results suggest that they are not incidental findings, but rather they appear in relation to phosphorylated tau accumulation, further highlighting the role of GVD in the process of phosphorylated tau accumulation.

Localization of CHMP2B‐immunoreactivity in the brainstem of Lewy body disease

Alpha‐synuclein (αS) is one of the major constituents of Lewy bodies (LBs). Several lines of evidence suggest that the autophagy‐lysosome pathway (ALP) is involved in the removal of αS. We have previously reported that granulovacuolar degeneration (GVD) in neurons involved a subunit of the endosomal sorting complexes required for transport (ESCRT). In this study, we examined the association between alpha‐synucleinopathy and autophagy through immunohistochemical analysis of charged multivesicular body protein 2B (CHMP2B), a component of the ESCRT‐pathway. We examined the brainstems of 17 patients with Parkinsons disease (PD), incidental Lewy body disease (ILBD), multiple system atrophy (MSA), and Alzheimers disease (AD) immunohistochemically using antibodies against phosphorylated αS (pαS), phosphorylated tau and CHMP2B. LBs and a proportion of glial cytoplasmic inclusions (GCIs) were immunopositive for pαS and CHMP2B. Neurons containing CHMP2B‐immunoreactive granules were detected in PD and ILBD, but not in MSA and AD brains. CHMP2B immunoreactivity was increased in the dorsal motor nucleus of the vagus nerve (DMNX) in PD and ILBD brains, relative to that in MSA and AD. These findings indicate that the ESCRT‐pathway is implicated in the formation of αS inclusions, especially in PD and ILBD.

Cyclin-dependent kinase 5 immunoreactivity for granulovacuolar degeneration.

In addition to senile plaque and neurofibrillary tangles, granulovacuolar degeneration is a hallmark of Alzheimer’s disease. A number of tau kinases, such as c-jun N-terminal kinase (JNK), glycogen-synthase kinase-3&bgr; (GSK3&bgr;), and casein kinase 1 (CK1), have been reported to be markers of granulovacuolar degeneration. In addition, cyclin-dependent kinase 5 (CDK5), which phosphorylates tau, has been shown to be abundantly expressed in neurofibrillary tangles in the hippocampus. CDK5 has a unique staining pattern, and therefore, has the potential to be a novel marker for granulovacuolar degeneration. In this study, we investigated the ability of CDK5 to be a marker for granulovacuolar degeneration using immunohistochemical analysis. Four Alzheimer’s disease cases, three myotonic dystrophy (MyD) cases, and three control cases were subjected to immunohistochemistry and immunofluorescent techniques using anti-CDK5, anti-charged multivesicular body protein 2B (CHMP2B), anti-pSmad2/3, anti-ubiquitin (Ub), anti-phospho-TDP-43 and AT8 antibodies. Some CDK5-positive granules were morphologically similar to granulovacuolar degeneration intraluminal granules, and these granules overlapped with those immunopositive for pSmad2/3, Ub and phospho-TDP-43 established granulovacuolar degeneration markers. Moreover, CDK5-positive granulovacuolar degeneration and phosphorylated tau colocalized in pyramidal neurons in Alzheimer’s disease and MyD cases. The numbers of CDK5-positive granules showed an inverse relationship with the degree of mature neurofibrillary tangles in each cell, as was the case with CHMP2B-positive granulovacuolar degeneration granules and neurofibrillary tangles. The presence of tau kinases including CDK5 in granulovacuolar degeneration might implicate that granulovacuolar degeneration is structurally involved in tau modification.

Nutritional support by “conventional” percutaneous endoscopic gastrostomy feeding may not result in weight gain in Parkinson’s disease

Percutaneous endoscopic gastrostomy (PEG) is being increasingly used in patients with neurogenic dysphagia [4–7] to improve their nutrition. However, only sparse information is available on the use of PEG for long-term feeding in patients with chronic neurological disorders including Parkinson’s disease (PD). Here, we carried out a study to evaluate changes in the body weight of PD patients with neurogenic dysphagia before and after PEG. All patients who underwent the ‘‘pull’’ method of 20–22 Fr PEG at Kobatake Hospital from 1996–2009 were eligible for inclusion in the study. Inclusion criteria were the availability of complete weight and height data in the medical records for the study period and successful PEG. Body weight was recorded at 6 and 12 months pre-operatively, at baseline, and at 3, 6, 9, and 12 months following PEG. After PEG, an appropriate formula and feeding regimen was determined by the nutrition support team (NST). Body weight on the morning of the PEG procedure was used as the baseline index weight for comparison to the preand post-operative values. Comparisons of mean weights between time points were analyzed by the paired Student’s t test (Microsoft Excel 2010, Redmond, WA). During the study period, 8 subjects (5male, 3 female) met the inclusion criteria. The average age of the subjects was 79 years. Other clinical characteristics are shown in Table 1. Overall, the average weight loss over 12 months preoperatively was 8 kg (P \ 0.03), whereas the average weight loss over 12 months after PEG was 3 kg, which did not reach statistical significance (Fig. 1a). Body weight changes by gender are outlined in Fig. 1b and c. Both males and females showed significant weight loss over 12 months pre-operatively, with an average loss of 9 and 5 kg, respectively (P \ 0.03, Fig. 1b, c). Interestingly, while males lost an average of 6 kg in the 12 month postoperative period (P \ 0.05), females had an average weight gain of 3 kg, which did not reach statistical significance (P = 0.11). The results of our study suggest that, despite the appropriate formula and feeding regimen as determined by the NST (25–30 kcal/kg for a bedridden patient), this ‘‘conventional’’ PEG feeding may not result in weight gain in PD. On the other hand, Britton et al. [4] examined 32 younger patients with chronic neurological disorders and showed that PEG was an effective method for feeding, with all patients having weight gain and an improvement in their quality of life. Given that weight loss is one of the indications for PEG feeding [5], the fact that weight changes after PEG may vary according to age or disorder should be taken into account by neurologists in their management of patients who require PEG feeding. The reason for the post-operative weight loss in male PD patients is unclear. As our patients were all bedridden and the required calories and nutrients were administered by PEG feeding, it seems unlikely that decreased energy Y. Yamazaki (&) M. Matsumoto Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan e-mail: yyamazak@hiroshima-u.ac.jp

The purple urine bag syndrome

An 83-year-old bedridden woman with a urinary drainage catheter for more than 3 years, hospitalised for advanced corticobasal degeneration, presented with a purple discolouration of the urine and the drainage bag (fig 1). Interestingly, the urine in the catheter from within the patient had …

Trigeminal neuropathy from perineural spread of an amyloidoma detected by blink reflex and thin-slice magnetic resonance imaging

The purpose of this study was to describe a trigeminal neuropathy caused by the perineural spread of an amyloidoma. A 62‐year‐old woman had an amyloidoma of the Gasserian ganglion that was hypointense on T2‐weighted images; the lesion was enhanced by gadolinium on thin‐slice magnetic resonance imaging. There was no evidence of systemic amyloidosis or underlying inflammatory or neoplastic disorders. Her blink reflex and thin‐slice magnetic resonance imaging demonstrated that the right trigeminal nerve was involved. A rare trigeminal neuropathy resulted from the perineural spread of a primary amyloidoma that was difficult to detect by conventional magnetic resonance imaging. Muscle Nerve, 2010