Potential neuron-autonomous Purkinje cell degeneration by 2',3'-cyclic nucleotide 3'-phosphodiesterase promoter/Cre-mediated autophagy impairments.

Studies of neuroglial interaction largely depend on cell-specific gene knockout (KO) experiments using Cre recombinase. However, genes known as glial-specific genes have recently been reported to be expressed in neuroglial stem cells, leading to the possibility that a glia-specific Cre driver results in unwanted gene deletion in neurons, which may affect sound interpretation. 2',3'-Cyclic nucleotide 3'-phosphodiesterase (CNP) is generally considered to be an oligodendrocyte (OL) marker. Accordingly, Cnp promoter-controlled Cre recombinase has been used to create OL-specific gene targeting mice. However, in this study, using Rosa26-tdTomato-reporter/Cnp-Cre mice, we found that many forebrain neurons and cerebellar Purkinje neurons belong to the lineages of Cnp-expressing neuroglial stem cells. To answer whether gene targeting by Cnp-Cre can induce neuron-autonomous defects, we conditionally deleted an essential autophagy gene, Atg7, in Cnp-Cre mice. The Cnp-Cre-mediated Atg7 KO mice showed extensive p62 inclusion in neurons, including cerebellar Purkinje neurons with extensive neurodegeneration. Furthermore, neuronal areas showing p62 inclusion in Cnp-Cre-mediated Atg7 KO mice overlapped with the neuronal lineage of Cnp-expressing neuroglial stem cells. Moreover, Cnp-Cre-mediated Atg7-KO mice did not develop critical defects in myelination. Our results demonstrate that a large population of central neurons are derived from Cnp-expressing neuroglial stem cells; thus, conditional gene targeting using the Cnp promoter, which is known to be OL-specific, can induce neuron-autonomous phenotypes.

A three-dimensional human neural cell culture model of Alzheimer's disease.

Alzheimer's disease is the most common form of dementia, characterized by two pathological hallmarks: amyloid-ß plaques and neurofibrillary tangles. The amyloid hypothesis of Alzheimer's disease posits that the excessive accumulation of amyloid-ß peptide leads to neurofibrillary tangles composed of aggregated hyperphosphorylated tau. However, to date, no single disease model has serially linked these two pathological events using human neuronal cells. Mouse models with familial Alzheimer's disease (FAD) mutations exhibit amyloid-ß-induced synaptic and memory deficits but they do not fully recapitulate other key pathological events of Alzheimer's disease, including distinct neurofibrillary tangle pathology. Human neurons derived from Alzheimer's disease patients have shown elevated levels of toxic amyloid-ß species and phosphorylated tau but did not demonstrate amyloid-ß plaques or neurofibrillary tangles. Here we report that FAD mutations in ß-amyloid precursor protein and presenilin 1 are able to induce robust extracellular deposition of amyloid-ß, including amyloid-ß plaques, in a human neural stem-cell-derived three-dimensional (3D) culture system. More importantly, the 3D-differentiated neuronal cells expressing FAD mutations exhibited high levels of detergent-resistant, silver-positive aggregates of phosphorylated tau in the soma and neurites, as well as filamentous tau, as detected by immunoelectron microscopy. Inhibition of amyloid-ß generation with ß- or γ-secretase inhibitors not only decreased amyloid-ß pathology, but also attenuated tauopathy. We also found that glycogen synthase kinase 3 (GSK3) regulated amyloid-ß-mediated tau phosphorylation. We have successfully recapitulated amyloid-ß and tau pathology in a single 3D human neural cell culture system. Our unique strategy for recapitulating Alzheimer's disease pathology in a 3D neural cell culture model should also serve to facilitate the development of more precise human neural cell models of other neurodegenerative disorders.

Alzheimer's in 3D culture: challenges and perspectives.

Alzheimer's disease (AD) is the most common cause of dementia, and there is currently no cure. The "ß-amyloid cascade hypothesis" of AD is the basis of current understanding of AD pathogenesis and drug discovery. However, no AD models have fully validated this hypothesis. We recently developed a human stem cell culture model of AD by cultivating genetically modified human neural stem cells in a three-dimensional (3D) cell culture system. These cells were able to recapitulate key events of AD pathology including ß-amyloid plaques and neurofibrillary tangles. In this review, we will discuss the progress and current limitations of AD mouse models and human stem cell models as well as explore the breakthroughs of 3D cell culture systems. We will also share our perspective on the potential of dish models of neurodegenerative diseases for studying pathogenic cascades and therapeutic drug discovery.

Pediatric intracerebral histiocytic sarcoma with rhabdoid features: Case report and literature review.

A 16-year-old boy presented with marked weight loss, weakness of the left extremities and dizziness of 2 months duration and vomiting for 2 days. Brain MRI showed an approximately 6.5 × 5.3 cm-sized huge heterogeneous enhancing mass located in the corpus callosum, extending into the lateral ventricle. Open biopsy showed that the lesion consisted of lymphoplasmacytes and plump histiocytes with rhabdoid morphology, which were stained with S-100 protein, CD68 (KP1) and negative for CD1a. Histiocytic tumor was initially diagnosed. Chemotherapy using methotrexate, 6-mercaptopurine, vinblastine, interferon-alpha and dexamethasone was performed. After 5 months, partial removal was done. Microscopically, plump and bizarre tumor cells as well as rhabdoid features were found. Occasional spindle cells and necrosis were also found. These cells were positive for CD163, CD68, lysozyme, CD4, INI-1 and BRG1. BRAF V600E mutation was detected. The lesion was finally diagnosed as histiocytic sarcoma. Radiotherapy (6000 cGy in 30 fractions) was done. Both cerebral and extracerebral histiocytic sarcomas have long been diagnosed by unclarified criteria; its rarity as well as previously unclarified criteria can easily lead to a misinterpretation. Histiocytic sarcoma of the CNS is exceptionally rare in children, associated with an exceptionally poor prognosis. To date, only seven cases of pediatric cerebral histiocytic sarcomas have been reported. The present case is the first pediatric case showing BRAF V600E-mutated intracerebral histiocytic sarcoma.

Amyloid-beta-activated human microglial cells through ER-resident proteins.

Microglial activation in the central nervous system is a key event in the neuroinflammation that accompanies neurodegenerative diseases such as Alzheimer's disease (AD). Among cytokines involved in microglial activation, amyloid ß (Aß) peptide is known to be a key molecule in the induction of diverse inflammatory products, which may lead to chronic inflammation in AD. However, proteomic studies of microglia in AD are limited due to lack of proper cell or animal model systems. In this study, we performed a proteomic analysis of Aß-stimulated human microglial cells using SILAC (stable isotope labeling with amino acids in cell culture) combined with LC-MS/MS. Results showed that 60 proteins increased or decreased their abundance by 1.5 fold or greater. Among these, ER-resident proteins such as SERPINH1, PDIA6, PDIA3, and PPIB were revealed to be key molecular biomarkers of human microglial activation by validation of the proteomic results by immunostaining, PCR, ELISA, and Western blot. Taken together, our data suggest that ER proteins play an essential role in human microglial activation by Aß and may be important molecular therapeutic targets for treatment of AD.

Human temporal lobe epilepsy analyses by tissue proteomics.

Although there are many types of epilepsy, temporal lobe epilepsy (TLE) is probably in humans the most common and most often studied. TLE represents 40% of the total epilepsy form of the disease and is difficult to treat. Despite a wealth of descriptive data obtained from the disease history of patients, the EEG recording, imaging techniques, and histological studies, the epileptogenic process remains poorly understood. However, it is unlikely that a single factor or a single mechanism can cause many changes associated with this neuropathological phenomenon. MALDI mass spectrometry imaging (MSI) coupled to protein identification, because of its ability to study a wide range of molecules, appears to be suitable for the preparation of molecular profiles in TLE. Seven neuropeptides have been have been identified in Dental gyrus regions of the hippocampus in relation with TLE pathology. Shot-gun studies taking into account gender influence have been performed. Tissue microextraction from control (10) toward 10 TLE patients have been analyzed after trypsin digestion followed by separation on nanoLC coupled to LTQ orbitrap. From the shot-gun analyses, results confirmed the presence of specific neuropeptides precursors and receptors in TLE patients as well as proteins involved in axons regeneration including neurotrophins, ECM proteins, cell surface proteins, membrane proteins, G-proteins, cytoskeleton proteins and tumor suppressors. Among the tumor suppressors identified, the Leucine-rich glioma inactivated 1 (LGI1) protein was found. LGI1 gene recently been demonstrated being implicated in heritability of TLE. We have also demonstrate the presence a complete profile of tumor suppressors in TLE patients, 7 have been identified. Refining this analysis taken into account the gender influence in both control and in TLE reflected the presence of specific proteins between male and female and thus mechanisms in pathology development could be completely different.

BACE1 and presenilin/γ-secretase regulate proteolytic processing of KCNE1 and 2, auxiliary subunits of voltage-gated potassium channels.

BACE1 and presenilin (PS)/γ-secretase play a major role in Alzheimer's disease pathogenesis by regulating amyloid-ß peptide generation. We recently showed that these secretases also regulate the processing of voltage-gated sodium channel auxiliary ß-subunits and thereby modulate membrane excitability. Here, we report that KCNE1 and KCNE2, auxiliary subunits of voltage-gated potassium channels, undergo sequential cleavage mediated by either α-secretase and PS/γ-secretase or BACE1 and PS/γ-secretase in cells. Elevated α-secretase or BACE1 activities increased C-terminal fragment (CTF) levels of KCNE1 and 2 in human embryonic kidney (HEK293T) and rat neuroblastoma (B104) cells. KCNE-CTFs were then further processed by PS/γ-secretase to KCNE intracellular domains. These KCNE cleavages were specifically blocked by chemical inhibitors of the secretases in the same cell models. We also verified our results in mouse cardiomyocytes and cultured primary neurons. Endogenous KCNE1- and KCNE2-CTF levels increased by 2- to 4-fold on PS/γ-secretase inhibition or BACE1 overexpression in these cells. Furthermore, the elevated BACE1 activity increased KCNE1 processing and shifted KCNE1/KCNQ1 channel activation curve to more positive potentials in HEK cells. KCNE1/KCNQ1 channel is a cardiac potassium channel complex, and the positive shift would lead to a decrease in membrane repolarization during cardiac action potential. Together, these results clearly showed that KCNE1 and KCNE2 cleavages are regulated by BACE1 and PS/γ-secretase activities under physiological conditions. Our results also suggest a functional role of KCNE cleavage in regulating voltage-gated potassium channels.

Comparing clinical outcomes of vitamin K antagonists vs non-vitamin K antagonists in anticoagulant therapy for mesenteric venous thrombosis.

OBJECTIVE: Non-vitamin K antagonist oral anticoagulants have shown similar efficacy and lower bleeding rates than vitamin K antagonists for venous thromboembolism. However, this has not been proven in mesenteric vein thrombosis. This study aimed to compare the clinical outcomes of vitamin K antagonists and non-vitamin K antagonist oral anticoagulants. METHODS: Between January 2014 and July 2022, mesenteric vein thrombosis was diagnosed on computed tomography in 225 patients in a tertiary hospital. Among them, a total of 44 patients who underwent long-term anticoagulation therapy over 3 months were enrolled in this study. Patients were divided into two groups based on the anticoagulant used: vitamin K antagonists (Group 1, n = 21) and non-vitamin K antagonist oral anticoagulants (Group 2, n = 23). The efficacy outcomes were symptom recurrence and thrombus resolution on follow-up computed tomography, and the safety outcome was bleeding complications. RESULTS: The median age of the patients was 56 years (range, 46-68 years), and 52% were men. The most common risk factors were unprovoked intra-abdominal infections (30%). The median duration of anticoagulation therapy was 13 months (20 months in Group 1 vs 6 months in Group 2; P = .076). Of the 44 patients, 17 (39%) received the standard treatment. The median follow-up period was longer in Group 1 than in Group 2 (57 vs 28 months; P = .048). No recurrence of mesenteric vein thrombosis-related symptoms were observed in either group. The median duration of follow-up computed tomography was 31 months (42 months in Group 1 vs 18 months in Group 2; P = .064). Computed tomography revealed complete thrombus resolution, partial resolution, and no changes in 71%, 19%, and 10%, respectively (P = .075). Regarding bleeding complications, varix bleeding and melena developed in two patients in Group 2, and anticoagulation treatment thereafter ceased. CONCLUSIONS: Despite the short follow-up duration in the non-vitamin K antagonist oral anticoagulants group, there was no clinically significant difference in the thrombus resolution rate or bleeding complications when compared with the vitamin K antagonists group. Although research on the long-term effects of non-vitamin K antagonist oral anticoagulants in patients is limited, non-vitamin K antagonist oral anticoagulants can be considered an alternative to conventional treatments.

Selective induction of Rab9-dependent alternative mitophagy using a synthetic derivative of isoquinoline alleviates mitochondrial dysfunction and cognitive deficits in Alzheimer's disease models.

Rationale: Promotion of mitophagy is considered a promising strategy for the treatment of neurodegenerative diseases including Alzheimer's disease (AD). The development of mitophagy-specific inducers with low toxicity and defined molecular mechanisms is essential for the clinical application of mitophagy-based therapy. The aim of this study was to investigate the potential of a novel small-molecule mitophagy inducer, ALT001, as a treatment for AD. Methods: ALT001 was developed through chemical optimization of an isoquinolium scaffold, which was identified from a chemical library screening using a mitophagy reporter system. In vitro and in vivo experiments were conducted to evaluate the potential of ALT001 as a mitophagy-targeting therapeutic agent and to investigate the molecular mechanisms underlying ALT001-induced mitophagy. The therapeutic effect of ALT001 was assessed in SH-SY5Y cells expressing mutant APP and mouse models of AD (5×FAD and PS2APP) by analyzing mitochondrial dysfunction and cognitive defects. Results: ALT001 specifically induces mitophagy both in vitro and in vivo but is nontoxic to mitochondria. Interestingly, we found that ALT001 induces mitophagy through the ULK1-Rab9-dependent alternative mitophagy pathway independent of canonical mitophagy pathway regulators such as ATG7 and PINK1. Importantly, ALT001 reverses mitochondrial dysfunction in SH-SY5Y cells expressing mutant APP in a mitophagy-dependent manner. ALT001 induces alternative mitophagy in mice and restores the decreased mitophagy level in a 5×FAD AD model mouse. In addition, ALT001 reverses mitochondrial dysfunction and cognitive defects in the PS2APP and 5×FAD AD mouse models. AAV-mediated silencing of Rab9 in the hippocampus further confirmed that ALT001 exerts its therapeutic effect through alternative mitophagy. Conclusion: Our results highlight the therapeutic potential of ALT001 for AD via alleviation of mitochondrial dysfunction and indicate the usefulness of the ULK1-Rab9 alternative mitophagy pathway as a therapeutic target.

Identification of trimethylation at C-terminal lysine of pilin in the cyanobacterium Synechocystis PCC 6803.

Various post-translational modifications (PTMs) of pilin in Synechocystis sp. PCC 6803 have been proposed. In this study, we investigated previously unidentified PTMs of pilin by mass spectrometry (MS). MALDI-TOF MS and TOF/TOF MS showed that the molecular mass of the C-terminal lysine of pilin was increased by 42Da, which could represent acetylation (ΔM=42.0470) or trimethylation (ΔM=42.0106). To discriminate between these isobaric modifications, the molecular mass of the C-terminal tryptic peptide was measured using 15T Fourier transform ion cyclotron resonance (FT-ICR) MS. The high magnetic field FT-ICR provided sub-ppm mass accuracy, revealing that the C-terminal lysine was modified by trimethylation. We could also detect the existence of mono- and di-methylation of the C-terminal lysine. Cells expressing a pilin point mutant with glutamine replacing the C-terminal lysine showed dramatically reduced motility and short pili. These findings suggest that trimethylation of pilin at the C-terminal lysine may be essential for the biogenesis of functional pili.

Primary hepatoid adenocarcinoma of the endometrium with a high alphafetoprotein level.

Primary hepatoid adenocarcinoma of the endometrium is a rare tumour that is similar to hepatocellular carcinoma histologically. Here, a patient with primary hepatoid carcinoma of the endometrium with a high alphafetoprotein (AFP) level (90,508 ng/mL) is presented in a 75-year-old woman. The pelvic computed tomography and magnetic resonance imaging suggested a submucosal leiomyoma with degeneration or endometrial hyperplasia. However, the endometrial biopsy revealed a primary hepatoid carcinoma of the endometrium. The patient underwent a staging laparotomy including a total abdominal hysterectomy, bilateral salpingo-oophorectomy and lymph node sampling with pelvic cytology. The AFP level can be highly elevated in hepatoid carcinoma of the endometrium.

Traumatic neuroma of remnant cystic duct mimicking duodenal subepithelial tumor: A case report.

BACKGROUND: Gastrointestinal subepithelial tumors (GSTs), incidentally detected during upper gastrointestinal (GI) endoscopy, may be lesions derived from the GI wall or may be caused by compression from external organs. In general, traumatic neuroma is a benign nerve tumor that results from postoperative nerve injury, occurring in the bile duct as one of the complications after cholecystectomy. This is the first case report demonstrating that neuroma of the cystic duct can be incorrectly perceived as a duodenal subepithelial tumor by compressing the duodenal wall. CASE SUMMARY: We report the case of a 72-year-old man with traumatic neuroma of the cystic duct after cholecystectomy. This tumor was mistaken for a duodenal subepithelial tumor on preoperative upper GI endoscopy and endoscopic ultrasonography due to external compression of the GI wall. The patient had no symptoms, and his laboratory test results were normal. However, in a series of follow-up endoscopies, the tumor was found to have grown in size, so it was surgically resected. The lesion was completely removed by laparoscopic endoscopic cooperative surgery. The patient was discharged on postoperative day 7 without complications. CONCLUSION: Traumatic neuroma of the cystic duct can be mistaken for GSTs in GI endoscopy.

Alteration in the glycan pattern of pilin in a nonmotile mutant of Synechocystis sp. PCC 6803.

Pilus-mediated motility is essential for the optimization of photosynthesis and environmental adaptation in the cyanobacterium Synechocystis sp. PCC 6803 (Syn6803). To identify the genes required for pilus-mediated motility in Syn6803, we applied a forward genetic approach using a Tn5 mutant library and reverse genetics using interposon mutagenesis. One of the identified genes, sll0899, bears sequence similarity to acyltransferases and nucleotidyltransferases. The sll0899 gene product is not involved in the transcription or translation of pilA1, which encodes pilin, the major component of pili. Instead, the sll0899::Cm(r) mutant produced pilins with increased molecular mass, suggesting the existence of different PTMs. Using MS, we found that the wild-type (WT) and mutant pilins were glycosylated between amino acids 67 and 75. Analyses by quantitative MS and high-pH anion exchange chromatography (HPAEC) revealed that the glycan in WT pilin is composed of xylose and fucose, whereas an additional sugar, rhamnose, was found in the glycan of sll0899::Cm(r). Our findings suggest that an alteration in the O-linked glycan of pilin is responsible for the loss of pilus-mediated motility in sll0899::Cm(r).

Differential expression of cell surface proteins in human bone marrow mesenchymal stem cells cultured with or without basic fibroblast growth factor containing medium.

Mesenchymal stem cells (MSCs) are multipotent cells, which have the capability to differentiate into various mesenchymal tissues such as bone, cartilage, fat, tendon, muscle, and marrow stroma. However, they lose the capability of multi-lineage differentiation after several passages. It is known that basic fibroblast growth factor (bFGF) increases growth rate, differentiation potential, and morphological changes of MSCs in vitro. In this report, we have used 2-DE coupled to MS to identify differentially expressed proteins at the cell membrane level in MSCs growing in bFGF containing medium. The cell surface proteins isolated by the biotin-avidin affinity column were separated by 2-DE in triplicate experiments. A total of 15 differentially expressed proteins were identified by quadrupole-time of flight tandem MS. Nine of the proteins were upregulated and six proteins were downregulated in the MSCs cultured with bFGF containing medium. The expression level of three actin-related proteins, F-actin-capping protein subunit alpha-1, actin-related protein 2/3 complex subunit 2, and myosin regulatory light chain 2, was confirmed by Western blot analysis. The results indicate that the expression levels of F-actin-capping protein subunit alpha-1, actin-related protein 2/3 complex subunit 2, and myosin regulatory light chain 2 are important in bFGF-induced morphological change of MSCs.

A Proteotranscriptomic-Based Computational Drug-Repositioning Method for Alzheimer's Disease.

Numerous clinical trials of drug candidates for Alzheimer's disease (AD) have failed, and computational drug repositioning approaches using omics data have been proposed as effective alternative approaches to the discovery of drug candidates. However, little multi-omics data is available for AD, due to limited availability of brain tissues. Even if omics data exist, systematic drug repurposing study for AD has suffered from lack of big data, insufficient clinical information, and difficulty in data integration on account of sample heterogeneity derived from poor diagnosis or shortage of qualified post-mortem tissue. In this study, we developed a proteotranscriptomic-based computational drug repositioning method named Drug Repositioning Perturbation Score/Class (DRPS/C) based on inverse associations between disease- and drug-induced gene and protein perturbation patterns, incorporating pharmacogenomic knowledge. We constructed a Drug-induced Gene Perturbation Signature Database (DGPSD) comprised of 61,019 gene signatures perturbed by 1,520 drugs from the Connectivity Map (CMap) and the L1000 CMap. Drugs were classified into three DRPCs (High, Intermediate, and Low) according to DRPSs that were calculated using drug- and disease-induced gene perturbation signatures from DGPSD and The Cancer Genome Atlas (TCGA), respectively. The DRPS/C method was evaluated using the area under the ROC curve, with a prescribed drug list from TCGA as the gold standard. Glioblastoma had the highest AUC. To predict anti-AD drugs, DRPS were calculated using DGPSD and AD-induced gene/protein perturbation signatures generated from RNA-seq, microarray and proteomic datasets in the Synapse database, and the drugs were classified into DRPCs. We predicted 31 potential anti-AD drug candidates commonly belonged to high DRPCs of transcriptomic and proteomic signatures. Of these, four drugs classified into the nervous system group of Anatomical Therapeutic Chemical (ATC) system are voltage-gated sodium channel blockers (bupivacaine, topiramate) and monamine oxidase inhibitors (selegiline, iproniazid), and their mechanism of action was inferred from a potential anti-AD drug perspective. Our approach suggests a shortcut to discover new efficacy of drugs for AD.

Recovery of the Psoas Muscle Index in Living Donors after a Right Lobe Hepatectomy for Liver Transplantation: A Single-Center Experience.

OBJECTIVE: The development of sarcopenia leads to adverse postoperative outcomes. However, no study has investigated perioperative loss in core muscle and the correlation between core muscle and residual liver volume in living donors for liver transplant. PATIENTS AND METHODS: A total of 457 adult healthy donors who underwent a right lobe hepatectomy without the middle hepatic vein for elective liver transplant were retrospectively analyzed. Abdominal computed tomography was performed within 1 month before surgery and the first week and 3 months after the surgery. The average psoas muscle area between lumbar vertebrae 3 and 4 was measured and normalized by height squared (psoas muscle index [PMI] = psoas muscle area/height2). The initial whole liver volume and remnant left lobe volume were measured on computed tomography images. RESULTS: The study cohort included 279 men (61.1%) and 178 women (38.9%). The median preoperative PMIs were 420.9 mm2/m2 (interquartile range, 360.6-487.0 mm2/m2) in men and 280.9 mm2/m2 (interquartile range, 243.5-318.7 mm2/m2) in women. The PMIs in men and women significantly decreased during the first week after surgery, and gradually recovered to preoperative levels during the first 3 months after surgery. Based on the ratio between the remnant left lobe and initial whole liver volume (≥30%), the increase in remnant left lobe volume was not correlated with the decrease in PMI on postoperative day 7. A postoperative U-shaped recovery in the core muscles was present in both male and female donors, independent of the remnant liver ratio. CONCLUSIONS: Despite the requirements of partial liver regeneration and surgical wound repair, healthy donors did not suffer from sustained core muscle loss after surgery.

p75 and neural cell adhesion molecule 1 can identify pathologic Schwann cells in peripheral neuropathies.

OBJECTIVE: Myelinated Schwann cells (SCs) in adult peripheral nerves dedifferentiate into immature cells in demyelinating neuropathies and Wallerian degeneration. This plastic SC change is actively involved in the myelin destruction and clearance as demyelinating SCs (DSCs). In inherited demyelinating neuropathy, pathologically differentiated and dysmyelinated SCs constitute the main nerve pathology. METHODS: We investigated whether this SC plastic status in human neuropathic nerves could be determined by patient sera to develop disease-relevant serum biomarkers. Based on proteomics analysis of the secreted exosomes from immature SCs, we traced p75 neurotrophin receptor (p75) and neural cell adhesion molecule 1 (NCAM) in the sera of patients with peripheral neuropathy. RESULTS: Enzyme-linked immunosorbent assay (ELISA) revealed that p75 and NCAM were subtype-specifically expressed in the sera of patients with peripheral neuropathy. In conjunction with these ELISA data, pathological analyses of animal models and human specimens suggested that the presence of DSCs in inflammatory neuropathy and of supernumerary nonmyelinating or dysmyelinating SCs in inherited neuropathy could potentially be distinguished by comparing the expression profiles of p75 and NCAM. INTERPRETATION: This study indicates that the identification of disease-specific pathological SC stages might be a valuable tool for differential diagnosis of peripheral neuropathies.

Island clustering analysis for the comparison of the membrane and the soluble protein fractions of human brain proteome.

A protein identified in multiple separate bands of a 1-D gel reflects variation in the molecular weight caused by alternative splicing, endoproteolytic cleavage, or PTMs, such as glycosylation or ubiquitination. To characterize such a protein distribution over the bands, we defined an entity called an 'island' as the band region including the bands of the same protein identified sequentially. We quantified the island distribution using a new variable called an Iscore. Previously, as described in Park et al.. (Proteomics 2006, 6, 4978-4986.), we analyzed human brain tissue using a multidimensional MS/MS separation method. Here, the new method of island analysis was applied to the previous proteome data. The soluble and membrane protein fractions of human brain tissue were reanalyzed using the island distribution. The proteome of the soluble fraction exhibited more variation in island positions than that of the membrane fraction. Through the island analysis, we identified protein modifications and protein complexes over the 1-D gel bands.

Hydrogel-incorporating unit in a well: 3D cell culture for high-throughput analysis.

The microfluidic 3D cell culture system has been an attractive model because it mimics the tissue and disease model, thereby expanding our ability to control the local cellular microenvironment. However, these systems still have limited value as quantitative assay tools due to the difficulties associated with the manipulation and maintenance of microfluidic cells, and their lack of compatibility with the high-throughput screening (HTS) analysis system. In this study, we suggest a microchannel-free, 3D cell culture system that has a hydrogel-incorporating unit integrated with a multi-well plate (24- to 96-well plate), which can provide better reproducibility in biological experiments. This plate was devised considering the design constraints imposed by various cell biology applications as well as by high-throughput analysis where the physical dimensions of the micro-features in the hydrogel-incorporating units were altered. We also demonstrated that the developed plate is potentially applicable to a variety of quantitative biochemical assays for qRT-PCR, Western blotting, and microplate-reader-based assays, such as ELISA, viability assay, and high content-screening (HCS) as well as the co-culture for biological studies. Human neural progenitor cells (hNPCs) that produce pathogenic Aß species for modeling Alzheimer's disease (AD) were three-dimensionally cultured, and the efficacy of the inhibitors of Aß production was assessed by ELISA in order to demonstrate the performance of this plate.

BACE1 Regulates Proliferation and Neuronal Differentiation of Newborn Cells in the Adult Hippocampus in Mice.

ß-Site amyloid precursor protein cleaving enzyme 1 (BACE1) is required for the production of ß-amyloid (Aß), one of the major pathogenic molecules of Alzheimer's disease (AD), and is therefore being actively pursued as a drug target for AD. Adult hippocampal neurogenesis (AHN) is a lifelong process that is known to be important for learning and memory and may have the potential to regenerate damaged neural tissue. In this study, we examined whether BACE1 regulates AHN, which holds important implications for its suitability as a drug target in AD. Cohorts of 2-month-old wild-type (BACE1+/+), heterozygous, and homozygous BACE1 knockout mice (BACE1+/- and BACE1-/-, respectively) were injected with 5-bromo-2'-deoxyuridine (BrdU) and sacrificed 1 day later to examine the impact of loss of BACE1 on neural precursor cell (NPC) proliferation in the adult brain. Parallel cohorts of mice were sacrificed 4 weeks after BrdU injection to determine the effects of BACE1 on survival and differentiation of newborn NPCs. We found that NPC proliferation was increased in BACE1-/- mice compared to BACE1+/+ mice, while no difference was observed in NPC survival across genotypes. Differentiation of NPCs to neuronal lineage was impaired in BACE1-/- mice. However, no differences were observed in astrogenesis, the proportion of immature neurons, or the production of oligodendrocytes across genotypes. Importantly, corresponding with a decrease in neuronal differentiation in the absence of a complementary increase in an alternate cell fate, BACE1-/- mice were found to have a pool of undifferentiated NPCs in the hippocampus compared to BACE1+/+ and BACE1+/- mice.