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1.
Neurobiol Dis ; 127: 432-448, 2019 07.
Article in English | MEDLINE | ID: mdl-30951849

ABSTRACT

Alzheimer's disease (AD) genetics implies a causal role for innate immune genes, TREM2 and CD33, products that oppose each other in the downstream Syk tyrosine kinase pathway, activating microglial phagocytosis of amyloid (Aß). We report effects of low (Curc-lo) and high (Curc-hi) doses of curcumin on neuroinflammation in APPsw transgenic mice. Results showed that Curc-lo decreased CD33 and increased TREM2 expression (predicted to decrease AD risk) and also increased TyroBP, which controls a neuroinflammatory gene network implicated in AD as well as phagocytosis markers CD68 and Arg1. Curc-lo coordinately restored tightly correlated relationships between these genes' expression levels, and decreased expression of genes characteristic of toxic pro-inflammatory M1 microglia (CD11b, iNOS, COX-2, IL1ß). In contrast, very high dose curcumin did not show these effects, failed to clear amyloid plaques, and dysregulated gene expression relationships. Curc-lo stimulated microglial migration to and phagocytosis of amyloid plaques both in vivo and in ex vivo assays of sections of human AD brain and of mouse brain. Curcumin also reduced levels of miR-155, a micro-RNA reported to drive a neurodegenerative microglial phenotype. In conditions without amyloid (human microglial cells in vitro, aged wild-type mice), Curc-lo similarly decreased CD33 and increased TREM2. Like curcumin, anti-Aß antibody (also reported to engage the Syk pathway, increase CD68, and decrease amyloid burden in human and mouse brain) increased TREM2 in APPsw mice and decreased amyloid in human AD sections ex vivo. We conclude that curcumin is an immunomodulatory treatment capable of emulating anti-Aß vaccine in stimulating phagocytic clearance of amyloid by reducing CD33 and increasing TREM2 and TyroBP, while restoring neuroinflammatory networks implicated in neurodegenerative diseases.


Subject(s)
Alzheimer Disease/genetics , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Brain/drug effects , Curcumin/pharmacology , Gene Expression/drug effects , Immunity, Innate/genetics , Microglia/drug effects , Alzheimer Disease/metabolism , Amyloid beta-Protein Precursor/genetics , Amyloid beta-Protein Precursor/metabolism , Animals , Disease Models, Animal , Disease Progression , Humans , Membrane Glycoproteins/metabolism , Mice , Mice, Transgenic , Microglia/metabolism , Phagocytosis/drug effects , Plaque, Amyloid/genetics , Plaque, Amyloid/metabolism , Receptors, Immunologic/metabolism , Sialic Acid Binding Ig-like Lectin 3/metabolism
2.
Orthop Traumatol Surg Res ; 102(8): 1109-1111, 2016 12.
Article in English | MEDLINE | ID: mdl-27816608

ABSTRACT

Paralabral cysts in the shoulder are a relatively rare pathology. It is sometimes difficult to detect the location of a paralabral cyst in the shoulder using arthroscopy, and it can be difficult to confirm sufficient decompression by arthroscopy. We describe the case of a 64-year-old woman who underwent arthroscopic decompression for a paralabral cyst in the shoulder. Indigo carmine was injected into the cyst under ultrasonography guidance just before the operation. The leakage point of indigo carmine was detected using arthroscopy. Arthroscopic decompression was performed until the indigo carmine was completely discharged. Her shoulder pain, limited range of motion, and muscle weakness during abduction and external rotation improved postoperatively. Magnetic resonance imaging confirmed the disappearance of the cyst. Arthroscopic decompression using an ultrasonography-guided injection of indigo carmine is a useful treatment for a paralabral cyst in the shoulder.


Subject(s)
Arthroscopy/methods , Coloring Agents , Cysts/surgery , Decompression, Surgical/methods , Indigo Carmine , Cysts/complications , Cysts/diagnostic imaging , Female , Humans , Magnetic Resonance Imaging , Middle Aged , Shoulder Joint/physiopathology , Shoulder Joint/surgery , Shoulder Pain/etiology
3.
Orthop Traumatol Surg Res ; 101(6): 715-9, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26315347

ABSTRACT

BACKGROUND: Magnetic resonance imaging is useful for evaluating the rotator cuff, but some tendinous insertions cannot be assessed using oblique sagittal, oblique coronal, and axial magnetic resonance (MR) images because of the presence of the partial volume effect. HYPOTHESIS: The purpose of this study was to determine whether radial-slice MR images could reveal normal rotator cuff insertions and rotator cuff tears more clearly than conventional MR images. PATIENTS AND METHODS: The study included 18 subjects with normal rotator cuffs and 30 with rotator cuff tears. MR images of rotator cuff insertions sliced into radial, oblique coronal, and axial sections were obtained. The extent to which normal rotator cuff insertions and rotator cuff tears were visualized in each of the three MR images was evaluated. RESULTS: The top to posterior portions of the rotator cuff insertions from 0° to 120° could be visualized in the radial MR images. In comparison, the posterior portions of the rotator cuff insertions could not be visualized around 45° in both the oblique coronal and axial MR images. DISCUSSION: These findings demonstrate that radial MR images are superior to the oblique coronal and axial MR images regarding their ability to accurately visualize rotator cuff insertions. Radial MR images also revealed greater detail around 45° in the posterior area of the rotator cuff tears than the oblique coronal and axial MR images. Radial MR images are particularly useful for visualizing clinically important posterosuperior rotator cuff tears. LEVEL OF EVIDENCE: Level III - Diagnostic study.


Subject(s)
Magnetic Resonance Imaging/methods , Rotator Cuff Injuries , Rotator Cuff/pathology , Tendon Injuries/diagnosis , Adolescent , Adult , Aged , Arthroscopy , Female , Humans , Male , Middle Aged , Rupture , Young Adult
4.
Cell Death Dis ; 5: e1332, 2014 Jul 17.
Article in English | MEDLINE | ID: mdl-25032855

ABSTRACT

We recently demonstrated that endoplasmic reticulum (ER) stress induces sigma-1 receptor (Sig-1R) expression through the PERK pathway, which is one of the cell's responses to ER stress. In addition, it has been demonstrated that induction of Sig-1R can repress cell death signaling. Fluvoxamine (Flv) is a selective serotonin reuptake inhibitor (SSRI) with a high affinity for Sig-1R. In the present study, we show that treatment of neuroblastoma cells with Flv induces Sig-1R expression by increasing ATF4 translation directly, through its own activation, without involvement of the PERK pathway. The Flv-mediated induction of Sig-1R prevents neuronal cell death resulting from ER stress. Moreover, Flv-induced ER stress resistance reduces the infarct area in mice after focal cerebral ischemia. Thus, Flv, which is used frequently in clinical practice, can alleviate ER stress. This suggests that Flv could be a feasible therapy for cerebral diseases caused by ER stress.


Subject(s)
Endoplasmic Reticulum Stress/drug effects , Fluvoxamine/pharmacology , Receptors, sigma/genetics , Up-Regulation/drug effects , Activating Transcription Factor 4/genetics , Activating Transcription Factor 4/metabolism , Animals , Apoptosis/drug effects , HEK293 Cells , Humans , Male , Mice , Mice, Knockout , Neurons/cytology , Neurons/drug effects , Neurons/metabolism , Receptors, sigma/metabolism , Signal Transduction , Sigma-1 Receptor
6.
Genes Brain Behav ; 8(4): 473-80, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19566714

ABSTRACT

Schizophrenia is a common polygenic disease in distinct populations, while spinocerebellar ataxia type 17 (SCA17) is a rare autosomal dominant neurodegenerative disorder. Both diseases involve psychotic symptoms. SCA17 is caused by an expanded polyglutamine tract in the TATA box-binding protein (TBP) gene. In the present study, we investigated the association between schizophrenia and CAG repeat length in common TBP alleles with fewer than 42 CAG repeats in a Japanese population (326 patients with schizophrenia and 116 healthy controls). We found that higher frequency of alleles with greater than 35 CAG repeats in patients with schizophrenia compared with that in controls (p = 0.042). We also examined the correlation between CAG repeats length and age at onset of schizophrenia. We observed a negative correlation between the number of CAG repeats in the chromosome with longer CAG repeats out of two chromosomes and age at onset of schizophrenia (p = 0.020). We further provided evidence that TBP genotypes with greater than 35 CAG repeats, which were enriched in patients with schizophrenia, were significantly associated with hypoactivation of the prefrontal cortex measured by near-infrared spectroscopy during the tower of Hanoi, a task of executive function (right PFC; p = 0.015, left PFC; p = 0.010). These findings suggest possible associations of the genetic variations of the TBP gene with risk for schizophrenia, age at onset and prefrontal function.


Subject(s)
Prefrontal Cortex/physiopathology , Schizophrenia/epidemiology , Schizophrenia/genetics , TATA-Box Binding Protein/genetics , Adult , Age of Onset , Alleles , Female , Gene Frequency , Humans , Japan , Male , Middle Aged , Neuropsychological Tests , Repetitive Sequences, Nucleic Acid , Risk , Schizophrenia/physiopathology , Spectroscopy, Near-Infrared
7.
Clin Exp Dermatol ; 34(6): 718-20, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19077097

ABSTRACT

Granulomatous mycosis fungoides (MF) is a rare subtype of MF, characterized by the histological presence of a granulomatous reaction, but distinct clinical characteristics are not present. A 41-year-old healthy man presented with poikiloderma, ichthyosis and erythematous scaly plaque. Histological examination of a biopsy taken from poikilodermic skin showed a granulomatous reaction to epidermotropic atypical lymphocytes. However, in other areas there were only findings of conventional MF without granuloma. Granulomatous MF may be associated with poikiloderma.


Subject(s)
Mycosis Fungoides/pathology , Rothmund-Thomson Syndrome/pathology , Skin/pathology , Adult , Biopsy , Diagnosis, Differential , Humans , Male , Mycosis Fungoides/drug therapy , Recurrence , Rothmund-Thomson Syndrome/drug therapy
8.
Cell Death Differ ; 15(2): 364-75, 2008 Feb.
Article in English | MEDLINE | ID: mdl-18049481

ABSTRACT

The endoplasmic reticulum (ER) stress response is a defense system for dealing with the accumulation of unfolded proteins in the ER lumen. Recent reports have shown that ER stress is involved in the pathology of some neurodegenerative diseases and cerebral ischemia. In a screen for compounds that induce the ER-mediated chaperone BiP (immunoglobulin heavy-chain binding protein)/GRP78 (78 kDa glucose-regulated protein), we identified BiP inducer X (BIX). BIX preferentially induced BiP with slight inductions of GRP94 (94 kDa glucose-regulated protein), calreticulin, and C/EBP homologous protein. The induction of BiP mRNA by BIX was mediated by activation of ER stress response elements upstream of the BiP gene, through the ATF6 (activating transcription factor 6) pathway. Pretreatment of neuroblastoma cells with BIX reduced cell death induced by ER stress. Intracerebroventricular pretreatment with BIX reduced the area of infarction due to focal cerebral ischemia in mice. In the penumbra of BIX-treated mice, ER stress-induced apoptosis was suppressed, leading to a reduction in the number of apoptotic cells. Considering these results together, it appears that BIX induces BiP to prevent neuronal death by ER stress, suggesting that it may be a potential therapeutic agent for cerebral diseases caused by ER stress.


Subject(s)
Apoptosis/drug effects , Endoplasmic Reticulum/metabolism , Heat-Shock Proteins/metabolism , Molecular Chaperones/metabolism , Neurons/drug effects , Thiocyanates/pharmacology , Activating Transcription Factor 6/metabolism , Animals , Cell Line, Tumor , Cerebral Infarction/drug therapy , Cerebral Infarction/metabolism , Cerebral Infarction/pathology , Endoplasmic Reticulum Chaperone BiP , HSP70 Heat-Shock Proteins/metabolism , Humans , Membrane Proteins/metabolism , Mice , Mice, Knockout , Neurons/metabolism , Neurons/physiology , Oxidative Stress/drug effects , Thiocyanates/chemistry
9.
J Orthop Surg (Hong Kong) ; 15(3): 273-7, 2007 Dec.
Article in English | MEDLINE | ID: mdl-18162668

ABSTRACT

PURPOSE: To report outcomes of 87 consecutive patients treated with a proximal femoral nail (PFN) for trochanteric femoral fractures. METHODS: 17 men and 70 women aged 58 to 95 (mean, 85) years with trochanteric femoral fractures underwent PFN fixation using an intramedullary nail, a lag screw, and a hip pin. Fractures were classified according to the AO system; the most common fracture type was A2 (n=45), followed by A1 (n=36) and A3 (n=6). The position of the lag screw within the femoral head was measured. The lateral slide of the lag screw after fracture consolidation was measured by comparing the immediate postoperative and final anteroposterior radiographs. RESULTS: 90% of lag screws were placed in an optimal position. The length of lateral slide of the lag screw in stable A1 fractures was significantly less than that in unstable A2 fractures; it was over 10 mm in 7 of 45 patients with A2 fractures. Cut-out of lag screw did not occur, suggesting that free sliding of the lag screw facilitates direct impaction between fragments. CONCLUSION: A PFN is useful for the treatment of trochanteric femoral fractures.


Subject(s)
Bone Nails , Femoral Fractures/surgery , Fracture Fixation, Intramedullary/instrumentation , Aged , Aged, 80 and over , Female , Femoral Fractures/diagnostic imaging , Fracture Healing , Humans , Male , Middle Aged , Postoperative Complications , Radiography , Treatment Outcome
11.
J Neurochem ; 83(4): 1009-12, 2002 Nov.
Article in English | MEDLINE | ID: mdl-12421374

ABSTRACT

Non-steroidal anti-inflammatory drugs (NSAIDs) have been associated with reduced risk for Alzheimer's disease (AD) and selected NSAIDs racemates suppress beta-amyloid (Abeta) accumulation in vivo and Abeta42 production in vitro. Clinical use of NSAIDs for preventing or treating AD has been hampered by dose-limiting toxicity believed to be due to cyclooxygenase (COX)-inhibition that is reportedly not essential for selective Abeta42 reduction. Profens have racemates and R-enantiomers were supposed to be inactive forms. Here we demonstrate that R-ibuprofen and R-flurbiprofen, with poor COX-inhibiting activity, reduce Abeta42 production by human cells. Although these R-enantiomers inhibit nuclear factor-kappaB (NF-kappaB) activation and NF-kappaB can selectively regulate Abeta42, Abeta42 reduction is not mediated by inhibition of NF-kappaB activation. Because of its efficacy at lowering Abeta42 production and low toxicity profile, R-flurbiprofen is a strong candidate for clinical development.


Subject(s)
Amyloid beta-Peptides/antagonists & inhibitors , Amyloid beta-Peptides/metabolism , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Peptide Fragments/antagonists & inhibitors , Peptide Fragments/metabolism , Amyloid beta-Peptides/analysis , Amyloid beta-Protein Precursor/genetics , Amyloid beta-Protein Precursor/metabolism , Blotting, Western , Cell Line , Culture Media, Conditioned/chemistry , Culture Media, Conditioned/metabolism , Dose-Response Relationship, Drug , Flurbiprofen/pharmacology , Humans , Ibuprofen/pharmacology , Kidney/cytology , Kidney/drug effects , Kidney/metabolism , Mutation , NF-kappa B/antagonists & inhibitors , NF-kappa B/metabolism , Peptide Fragments/analysis , Peptides/pharmacology , Stereoisomerism , Transfection
12.
J Biol Chem ; 276(3): 2108-14, 2001 Jan 19.
Article in English | MEDLINE | ID: mdl-11031265

ABSTRACT

An alternative spliced form of the presinilin 2 (PS2) gene (PS2V) lacking exon 5 has previously been reported to be expressed in human brains in sporadic Alzheimer's disease (AD). PS2V encodes the amino-terminal portion of PS2, which contains residues Met1-Leu119 and 5 additional amino acid residues (SSMAG) at its carboxyl terminus. Here we report that PS2V protein impaired the signaling pathway of the unfolded protein response, similarly to familial AD-linked PS1 mutants and caused significant increases in the production of both amyloid beta40 and beta42. Interestingly, PS2V-encoding protein was expressed in neuropathologically affected neurons of the hippocampal CA1 region and temporal cortex in AD patients. These findings suggest that the aberrant splicing of the PS2 gene may be implicated in the neuropathology of sporadic AD.


Subject(s)
Alternative Splicing , Amyloid beta-Peptides/biosynthesis , Endoplasmic Reticulum/metabolism , Membrane Proteins/metabolism , Alzheimer Disease/metabolism , Animals , Brain/metabolism , Cell Line , Humans , Membrane Proteins/genetics , Mice , Presenilin-2 , Signal Transduction
13.
Psychiatry Clin Neurosci ; 54(2): 199-202, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10803815

ABSTRACT

A biological marker for normal pressure hydrocephalus (NPH) is beneficial for evaluation of its severity and of indications for shunt operation. Tau protein was initially considered as a biological marker in cerebrospinal fluid (CSF) from Alzheimer's patients. Recently, it has been demonstrated that degeneration in the brain causes elevation of tau in CSF. Therefore, the tau level in CSF from NPH patients was evaluated. Tau levels in CSF from NPH patients were significantly higher than that in controls. The tau levels were correlated with the severity of dementia, urinary incontinence, and gait disturbance in NPH. These results suggest that CSF tau may be useful as a biological marker for NPH to determine the level of neuronal degeneration.


Subject(s)
Hydrocephalus, Normal Pressure/diagnosis , tau Proteins/cerebrospinal fluid , Aged , Aged, 80 and over , Alzheimer Disease/cerebrospinal fluid , Alzheimer Disease/diagnosis , Biomarkers/cerebrospinal fluid , Dementia/cerebrospinal fluid , Dementia/diagnosis , Female , Humans , Hydrocephalus, Normal Pressure/cerebrospinal fluid , Hydrocephalus, Normal Pressure/etiology , Male , Middle Aged , Sensitivity and Specificity
14.
J Biol Chem ; 275(15): 11114-20, 2000 Apr 14.
Article in English | MEDLINE | ID: mdl-10753917

ABSTRACT

To elucidate the function of Bcl10, recently cloned as an apoptosis-associated gene mutated in MALT lymphoma, we identified its binding partner TRAF2, which mediates signaling via tumor necrosis factor receptors. In mammalian cells, low levels of Bcl10 expression promoted the binding of TRAF2 and c-IAPs. Conversely, excessive expression inhibited complex formation. Overexpressed Bcl10 reduced c-Jun N-terminal kinase activation and induced nuclear factor kappaB activation downstream of TRAF2. To determine whether overexpression of Bcl10 could perturb the regulation of apoptosis in vivo, we generated Bcl10 transgenic mice. In these transgenic mice, atrophy of the thymus and spleen was observed at postnatal stages. The morphological changes in these tissues were caused by acceleration of apoptosis in T cells and B cells. The phenotype of Bcl10 transgenic mice was similar to that of TRAF2-deficient mice reported previously, indicating that excessive expression of Bcl10 might deplete the TRAF2 function. In contrast, in the other organs such as the brain, where Bcl10 was expressed at high levels, no apoptosis was detected. The altered sensitivities to overexpressed Bcl10 may have been due to differences in signal responses to Bcl10 among cell types. Thus, Bcl10 was suggested to play crucial roles in the modulation of apoptosis associated with TRAF2.


Subject(s)
Adaptor Proteins, Signal Transducing , JNK Mitogen-Activated Protein Kinases , Proteins/physiology , Signal Transduction , Animals , B-Cell CLL-Lymphoma 10 Protein , Base Sequence , Enzyme Activation , Inhibitor of Apoptosis Proteins , MAP Kinase Kinase 4 , Mice , Mice, Transgenic , Mitogen-Activated Protein Kinase Kinases/metabolism , Molecular Sequence Data , NF-kappa B/metabolism , Neoplasm Proteins/physiology , TNF Receptor-Associated Factor 2 , Viral Proteins/physiology
15.
Brain Res Mol Brain Res ; 85(1-2): 85-90, 2000 Dec 28.
Article in English | MEDLINE | ID: mdl-11146110

ABSTRACT

It is well known that presenilin-1 (PS1) is involved in cleavage of amyloid precursor protein (APP) at the gamma-secretase site, and that the amino acids residues of D257 and D385 in PS1 are critical for this cleavage of APP and the endoproteolysis of itself. An alternatively spliced form of PS1 skipping exon 8 (PS1d8), which has D257A at the splice junction of exon 7/9, is expressed in human brain and in some cell lines. In this study, we examined production of Amyloid beta (A beta) and the endoproteolysis of the holoproteins in PS1d8-expressing neuroblastoma cells. Western blotting showed an absence of endoproteolysis in PS1d8. However, PS1d8 did not affect the production of A beta, which is different from the artificial point mutant PS1D257A. These results suggest that endoproteolysis of PS1 and gamma-secretase activity could be independent.


Subject(s)
Alternative Splicing/physiology , Amyloid beta-Peptides/metabolism , Membrane Proteins/genetics , Membrane Proteins/metabolism , Neurons/enzymology , Alzheimer Disease/genetics , Alzheimer Disease/metabolism , Amyloid Precursor Protein Secretases , Animals , Aspartic Acid Endopeptidases , Endopeptidases/metabolism , Exons , Humans , Mice , Neuroblastoma , Neurons/cytology , Plasmids , Presenilin-1 , RNA, Messenger/analysis , Transfection , Tumor Cells, Cultured
16.
Nat Cell Biol ; 1(8): 479-85, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10587643

ABSTRACT

Missense mutations in the human presenilin-1 (PS1) gene, which is found on chromosome 14, cause early-onset familial Alzheimer's disease (FAD). FAD-linked PS1 variants alter proteolytic processing of the amyloid precursor protein and cause an increase in vulnerability to apoptosis induced by various cell stresses. However, the mechanisms responsible for these phenomena are not clear. Here we report that mutations in PS1 affect the unfolded-protein response (UPR), which responds to the increased amount of unfolded proteins that accumulate in the endoplasmic reticulum (ER) under conditions that cause ER stress. PS1 mutations also lead to decreased expression of GRP78/Bip, a molecular chaperone, present in the ER, that can enable protein folding. Interestingly, GRP78 levels are reduced in the brains of Alzheimer's disease patients. The downregulation of UPR signalling by PS1 mutations is caused by disturbed function of IRE1, which is the proximal sensor of conditions in the ER lumen. Overexpression of GRP78 in neuroblastoma cells bearing PS1 mutants almost completely restores resistance to ER stress to the level of cells expressing wild-type PS1. These results show that mutations in PS1 may increase vulnerability to ER stress by altering the UPR signalling pathway.


Subject(s)
Endoplasmic Reticulum/metabolism , Heat-Shock Proteins , Membrane Proteins/metabolism , Mutation/genetics , Protein Folding , Signal Transduction , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Animals , Brain/metabolism , Brain/pathology , Calcimycin/pharmacology , Carrier Proteins/genetics , Carrier Proteins/metabolism , Cell Death/drug effects , Cell Line , Endoplasmic Reticulum/drug effects , Endoplasmic Reticulum Chaperone BiP , Endoribonucleases , HSP70 Heat-Shock Proteins/metabolism , Humans , Intracellular Membranes/metabolism , Membrane Proteins/genetics , Mice , Mice, Transgenic , Molecular Chaperones/genetics , Molecular Chaperones/metabolism , Neuroblastoma , Neurons/drug effects , Neurons/metabolism , Neurons/pathology , Phosphorylation , Presenilin-1 , Protein Binding , Protein Denaturation , Protein Serine-Threonine Kinases/genetics , Protein Serine-Threonine Kinases/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Signal Transduction/drug effects , Transfection , Tunicamycin/pharmacology
17.
Neuroscience ; 91(2): 695-706, 1999.
Article in English | MEDLINE | ID: mdl-10366026

ABSTRACT

Synaptosomal-associated protein 25 has been regarded as one of the target-associated soluble N-ethylmaleimide-sensitive fusion attachment protein receptors essential for exocytosis of vesicles in synapses. We have previously reported that cleavage of syntaxin, which is another target-associated soluble N-ethylmaleimide-sensitive fusion attachment protein receptor, with botulinum neurotoxin C1 resulted in inhibition of neurite extension and morphological changes including growth cone collapse and large vacuole formation. As an attempt to explore the mechanism of growth cone extension, we examined the ultrastructural localization of synaptosomal-associated protein 25 in growth cones with or without treatment of botulinum neurotoxin A, which cleaves synaptosomal-associated protein 25. In dorsal root ganglion neurons, light microscopy demonstrated synaptosomal-associated protein 25 immunoreactivity throughout the neurons, including the cell bodies, neurites and growth cones. Using electron microscopy, gold signals immunoreactive for synaptosomal-associated protein 25 were identified diffusely in the cytoplasm of the growth cones. In contrast, in PC-12 cells, a large number of gold signals were localized on the plasma membranes. High levels of signal were also found in the cytoplasm in the central region of the growth cones. We also confirmed that botulinum neurotoxin A treatment reduced neurite extension by about 50%. However, both in dorsal root ganglion neurons and in PC-12 cells we found no differences in the ultrastructure nor in the localization of synaptosomal-associated protein 25 between growth cones with and without toxin treatment. These results indicate that cleavage of synaptosomal-associated protein 25 inhibits growth cone extension in a manner different than that of syntaxin cleavage. The results of this study suggest the possibility that synaptosomal-associated protein 25 is involved in growth cone extension through a process independent of vesicle fusion.


Subject(s)
Axons/physiology , Botulinum Toxins, Type A/pharmacology , Ganglia, Spinal/physiology , Membrane Proteins , Nerve Tissue Proteins/metabolism , Neurites/physiology , Neurons/physiology , Animals , Axons/drug effects , Axons/ultrastructure , Ganglia, Spinal/cytology , Mice , Mice, Inbred Strains , Microscopy, Immunoelectron , Neurites/drug effects , Neurites/ultrastructure , Neurons/cytology , Neurons/drug effects , PC12 Cells , Rats , Synaptosomal-Associated Protein 25
18.
Brain Res Mol Brain Res ; 67(2): 231-8, 1999 Apr 20.
Article in English | MEDLINE | ID: mdl-10216221

ABSTRACT

To understand the molecular mechanisms underlying the developmental processes of the cerebral cortex, we screened genes whose mRNA expression was up-regulated in neonatal in the rat cortex to a greater extent than in adult by differential display and obtained five genes. Among these genes, we focused on pyrophosphate (isopentenyl diphosphate, dimethylallyl diphosphate: IPP) isomerase gene, the product of which is known as an enzyme of the mevalonate pathway. Rat IPP isomerase was recently cloned and the gene expression was shown to be dependent on the activation of the mevalonate pathway. Its expression and roles in the brain, however, have not been investigated hitherto. In the present study, Northern blots and in situ hybridization analysis showed that at embryonic stage weak signals for IPP mRNA were diffusely detected in the CNS, and the signal in the cortex became intense at postnatal day 1 and maximized in almost all neurons of all layers at postnatal day 7 with a subsequent reduction. At 8 weeks, the expression of IPP isomerase mRNA in neurons decreased, while it was detected in the oligodendrocytes in the regions containing abundant nerve fibers. These findings suggested that IPP isomerase contributes to postnatal neuronal maturation and myelination. We also demonstrated that IPP isomerase mRNA is induced after nerve axotomy, which suggests a relationship between neuronal regeneration and IPP isomerase. Taken together, these results suggest that elevation of IPP isomerase mRNA levels in neurons contributes to construction of nerve fibers both during the postnatal period in the cortex and their regeneration.


Subject(s)
Carbon-Carbon Double Bond Isomerases/genetics , Cerebral Cortex/cytology , Hypoglossal Nerve/enzymology , Mevalonic Acid/metabolism , Animals , Axotomy , Base Sequence , Blotting, Northern , Brain Chemistry/genetics , Cerebral Cortex/embryology , Cerebral Cortex/growth & development , Corpus Callosum/cytology , Corpus Callosum/embryology , Corpus Callosum/growth & development , DNA, Complementary , Demyelinating Diseases/genetics , Gene Expression Regulation, Developmental , Gene Expression Regulation, Enzymologic , Gene Library , Hemiterpenes , Hypoglossal Nerve/surgery , Molecular Sequence Data , Nerve Degeneration/enzymology , Nerve Degeneration/genetics , Nerve Regeneration/genetics , Neurons/enzymology , RNA, Messenger/analysis , Rats , Rats, Wistar
19.
J Biol Chem ; 274(12): 7975-81, 1999 Mar 19.
Article in English | MEDLINE | ID: mdl-10075695

ABSTRACT

DP5, which contains a BH3 domain, was cloned as a neuronal apoptosis-inducing gene. To confirm that DP5 interacts with members of the Bcl-2 family, 293T cells were transiently co-transfected with DP5 and Bcl-xl cDNA constructs, and immunoprecipitation was carried out. The 30-kDa Bcl-xl was co-immunoprecipitated with Myc-tagged DP5, suggesting that DP5 physically interacts with Bcl-xl in mammalian cells. Previously, we reported that DP5 is induced during neuronal apoptosis in cultured sympathetic neurons. Here, we analyzed DP5 gene expression and the specific interaction of DP5 with Bcl-xl during neuronal death induced by amyloid-beta protein (A beta). DP5 mRNA was induced 6 h after treatment with A beta in cultured rat cortical neurons. The protein encoded by DP5 mRNA showed a specific interaction with Bcl-xl. Induction of DP5 gene expression was blocked by nifedipine, an inhibitor of L-type voltage-dependent calcium channels, and dantrolene, an inhibitor of calcium release from the endoplasmic reticulum. These results suggested that the induction of DP5 mRNA occurs downstream of the increase in cytosolic calcium concentration caused by A beta. Moreover, DP5 specifically interacts with Bcl-xl during neuronal apoptosis following exposure to A beta, and its binding could impair the survival-promoting activities of Bcl-xl. Thus, the induction of DP5 mRNA and the interaction of DP5 and Bcl-xl could play significant roles in neuronal degeneration following exposure to A beta.


Subject(s)
Amyloid beta-Peptides/pharmacology , Apoptosis , Gene Expression Regulation , Neurons/physiology , Neuropeptides/biosynthesis , Neuropeptides/genetics , Proto-Oncogene Proteins c-bcl-2/metabolism , Alzheimer Disease/physiopathology , Amino Acid Sequence , Animals , Apoptosis/genetics , Apoptosis Regulatory Proteins , Cells, Cultured , Molecular Sequence Data , Protein Binding , RNA, Messenger/metabolism , Rats
20.
Psychiatry Clin Neurosci ; 52(1): 107-10, 1998 Feb.
Article in English | MEDLINE | ID: mdl-9682942

ABSTRACT

Microtubule-associated protein tau has been reported to be significantly increased in cerebrospinal fluid (CSF) of the patients with Alzheimer's disease (AD), which suggests that it is possibly a biological marker for the diagnosis of AD. The underlying mechanism of the increased tau level in CSF, however, is not known. In this study, the tau levels were compared between antemortem and postmortem CSF. The postmortem tau levels in CSF were significantly increased in all groups including AD, neurological control, and nondemented control. A striking elevation of CSF tau was observed during the postmortem change with the nondemented subjects. These findings may offer some insight into the understanding of the mechanism of the increased tau level in CSF with AD and other related disorders.


Subject(s)
Alzheimer Disease/diagnosis , Postmortem Changes , tau Proteins/cerebrospinal fluid , Aged , Alzheimer Disease/cerebrospinal fluid , Alzheimer Disease/pathology , Biomarkers/cerebrospinal fluid , Dementia/cerebrospinal fluid , Dementia/diagnosis , Dementia/pathology , Diagnosis, Differential , Female , Humans , Male , Reference Values
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