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Toshiyuki Yamada

Publications and source records attributed to Toshiyuki Yamada.

At least 19 recordsLinked to original sources
PubMed2006

Characteristics of sensory DRG neurons innervating the wrist joint in rats.

BACKGROUND: Wrist pain can be the result of trauma, or inflammatory processes such as arthritis or synovitis. There is evidence that sensory nerve fibers are present in the wrist joints of animals and humans; however, the sensory innervation pattern of the wrist, as well as the types of nerves innervating it, have not been clarified. The purpose of this study was to characterize the types of sensory dorsal root ganglion (DRG) neurons innervating the wrist joint in the rat. METHODS: In this study, retrograde neurotransport was combined with lectin affinity histochemistry and immunohistochemistry to characterize DRG neurons innervating the wrist joint in rats. We used 3 markers: calcitonin gene-related peptide (CGRP) as a marker of small, peptide-containing neurons associated with inflammatory pain; the glycoprotein binding the isolectin from Griffonia simplicifolia (IB4) for small, non-peptide-containing neurons related to transmission of pain following nerve injury; and neurofilament 200 (NF200) for small and large myelinated fibers. IB4-binding and CGRP-containing neurons are typically involved in pain sensation, whereas NF200 is associated with pain and proprioception. RESULTS: Neurons innervating the wrist joints, retrogradely labeled with fluoro-gold (FG), were distributed throughout DRGs from C6 to T1. Of all of the FG labeled neurons, the percentage of NF200 immunoreactive (IR) neurons and CGRP-IR neurons were 26% and 45%, respectively. The percentage of IB4-binding neurons was 3%, significantly less than the ratio of CGRP-IR neurons to the total FG labeled neurons. CONCLUSION: Under physiological conditions in rats, DRG neurons transmit several types of sensation from the wrist joint including proprioception and pain. Most of the labeled neurons were CGRP-IR peptide containing neurons. It is likely that these neurons are the predominant afferents for inflammatory pain signals from the wrist. Because peptide-containing neurons are associated with inflammatory pain, it is likely that the inflammation in the wrist joint causes wrist joint pain.

Animals↗
PubMed2006

Serum amyloid A (SAA)-induced remodeling of CSF-HDL.

Inflammation is a risk factor for Alzheimer's disease. Serum amyloid A (SAA) is an acute phase protein that dissociates apolipoprotein AI (apoAI) from plasma HDL. In cerebrospinal fluid (CSF), the SAA concentration is much higher in subjects with Alzheimer's disease than in controls. CSF-HDL is rich in apoE, which plays an important role as a ligand for lipoprotein receptors in the central nervous system (CNS). To clarify whether SAA dissociates apoE from CSF-HDL, we added recombinant SAA to CSF and determined the apoE distribution in the CSF using native two-dimensional gel electrophoresis. We found that SAA dissociated apoE from CSF-HDL in a dose-dependent manner. This effect was more evident in apoE4 carriers than in apoE3 or apoE2 carriers. After a 24-h incubation at 37 degrees C, SAA continuously dissociated apoE from CSF-HDL. Amyloid beta (Abeta) fragments (1-42) were bound to large CSF-HDL but not to apoE dissociated by SAA. In conclusion, SAA dissociates apoE from CSF-HDL. We postulate that inflammation in the CNS may impair Abeta clearance due to the loss of apoE from CSF-HDL.

Alzheimer Disease↗
PubMed2006

Measurement of serum amyloid A1 (SAA1), a major isotype of acute phase SAA.

Serum amyloid A (SAA), a plasma precursor of reactive amyloid deposits, is a multigene product. SAA1 and SAA2, with primary structures that are 93% identical (98 of 104 amino acids), behave as acute phase proteins, as demonstrated by their increasing levels in plasma. Heretofore, it has been understood that SAA1 predominates and functions as an isotype in plasma. However, accurate measurements differentiating the two isotypes have not been reported. In this study, using monoclonal antibodies specific for SAA1, we developed an enzyme-linked immunosorbent assay (ELISA) for SAA1. The levels and ratios of SAA1 in total SAA (TSAA) were investigated in healthy subjects and patients with rheumatoid arthritis (RA). The SAA1/TSAA ratio was 74 +/- 12% and 77 +/- 12% in healthy subjects and RA patients, respectively. In RA patients, the ratios were not influenced by SAA1 genotype, which has been proposed to affect plasma SAA values. The kinetics of SAA1 in inflamed patients undergoing hemodialysis was found to be parallel with total SAA and C-reactive protein. Finally, this study confirmed that SAA1 is a major isotype of acute phase SAA and may determine total SAA values. This specific assay could be used in the evaluation of SAA behavior in several clinical conditions.

Acute-Phase Reaction↗
PubMed2006

[Serum amyloid A (SAA)--pathogenicity and implication of appearance in plasma].

Serum amyloid A, SAA, is a plasma precursor of reactive amyloid fibrils and a sensitive acute phase reactant. The prolonged high production of SAA in chronic inflammation is the most essential for amyloidogenesis. In addition, impaired catabolism of SAA and SAA polymorphism may enhance disease development. SAA1 polymorphism affects the plasma concentration of SAA, probably because of differences in plasma clearance. Interestingly, amyloidogenic polymorphism (SAA1.3) does not show a high plasma SAA concentration. The true significance of SAA polymorphism in amyloidogenesis and physiological function is under investigation. Although SAA is produced primarily in the liver, attention has recently focused on extra-hepatic production and its physiological significance. In non-inflammatory conditions, the extrahepatic sites may constantly produce SAA while the expression may be suppressed in the liver. Therefore, it is possible that some parts of SAA in non-inflamed plasma are derived from extrahepatic sites such as adipose tissues and cells in the vascular wall.

Amyloidosis↗
PubMed2005

Nuclear localization of STAT5A modified with O-linked N-acetylglucosamine and early involution in the mammary gland of Hirosaki hairless rat.

Hirosaki hairless rat (HHR) is a mutant strain spontaneously derived from Sprague-Dawley rats (SDR), and its inheritance is autosomal recessive. In addition to hair loss, female HHRs show involution of the mammary gland at an early stage of lactation. In the present study we investigated the mammary gland development in HHR. Morphological examinations revealed that HHR mammary glands are underdeveloped in virgins and exhibit distended alveoli on day 1 of lactation (L1), followed by involution. Milk secretion was observed on L1 in HHR. Whey acidic protein and other proteins were increased in milk of HHR and heterozygous rats on SDS-polyacrylamide gel electrophoresis. Terminal deoxynucleotide transferase-mediated dUTP nick-end labeling assay revealed apoptosis induction in HHRs at an early stage of lactation. By Western blotting, signal transducer and activator of transcription (STAT) 5A levels in cytoplasmic and nuclear fractions of the mammary glands were not different between HHR and SDR on L1 and L7. Nuclear localization of STAT5A in HHR and SDR was confirmed by immunohistochemistry. Tyr-phosphorylated STAT5A was not detected in HHR but was detected in SDR nuclear fractions. Several proteins modified with O-linked N-acetylglucosamine (O-GlcNAc) were detected in HHR nuclear extract on L1, although not in SDR or heterozygous rats by Western blotting. When HHR nuclear extract was applied to wheat germ agglutinin-agarose, a part of STAT5A was recovered in bound fractions. STAT5A of SDR or heterozygous rat nuclei were not bound to the lectin. Electrophoretic mobility shift assay revealed that STAT5A modified with O-GlcNAc is bound to the STAT5-responsive element. These results indicate that the mammary glands of HHR showed terminal differentiation for a short period, followed immediately by involution. In HHR, STAT5A is modified with O-GlcNAc but is not Tyr-phosphorylated. This type of glycosylation is suggested to be involved in the transient activation of STAT5A in HHR.

Acetylglucosamine↗
PubMed2005

Impaired repressor activity and biological functions of PU.1 in MEL cells induced by mutations in the acetylation motifs within the ETS domain.

PU.1, a hematopoietic Ets transcription factor, is required for development of the lymphoid and myeloid lineages. We have previously shown that PU.1 functions as both a transcriptional activator and repressor through complex formation with CBP/p300 and HDAC1/mSin3A/MeCP2, respectively. To determine whether modification of PU.1 is responsible for switching its association between co-activators and co-repressors, we examined whether acetylation regulates the physical and functional activities of PU.1. PU.1 was acetylated in vivo and its repressor activity was reduced when the putative acetylation motifs in the Ets domain were mutated. The mutant cooperated with CBP similar to wild type PU.1, but insufficiently with GATA-1 and mSin3A. Whereas overexpression of wild type PU.1 induced differentiation block, growth inhibition, and apoptotic cell death in MEL erythroleukemia cells as we reported previously, overexpression of the mutant-acetylation motif PU.1 did not. Taken together, our data suggest that acetylation might regulate the biological functions of PU.1 in erythroid cells.

Acetylation↗
PubMed2005

Effect of a novel free radical scavenger, edaravone, on puromycin aminonucleoside induced nephrosis in rats.

Recent studies indicate that excessive production of oxidants plays a role in the pathogenesis of glomerular injury leading to proteinuria in patients with minimal-change nephrotic syndrome (MCNS). The novel free radical scavenger, edaravone (EDA), which was recently developed in Japan, is currently used in patients with stroke. We studied whether this new agent would be beneficial in patients with MCNS by its antioxidant activity and examined its effect on proteinuria in nephrosis induced by puromycin-aminonucleoside (PAN) in rats. Nineteen Wistar-Kyoto rats injected with PAN were assigned to four groups: group 1, without EDA (n=4); group 2, concomitant EDA injection from 1 day prior to PAN administration (n=5); group 3, concomitant EDA injection from 1 day after PAN administration (n=5); group 4, concomitant EDA injection from 3 days after PAN administration (n=5). Daily urinary excretions of protein and 8-hydroxy-2'-deoxyguanosine (8-OHdG), a new sensitive marker of oxidative DNA damage in vivo, were measured in each group from the 1st to the 30th day after PAN injection. In group 1 proteinuria developed from the 5th day and reached the peak level on the 9th day. In groups 2, 3, and 4 proteinuria did not appear until the 6th day. The excretions in urinary protein and 8-OHdG were significantly lower in groups 2, 3, and 4 than group 1 on days 5, 9, and 25. In conclusion, EDA could delay and ameliorate the urinary protein excretion in accordance with the urinary 8-OHdG excretion in PAN-induced nephrosis.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2005

Synthesis of porphyrin-introduced silica gels by sol-gel process.

Using a hydroxyl group appended free base porphyrin derivative (HP), porphyrin-introduced silica gels were synthesized by a sol-gel process. The HP content in the materials linearly increased with increasing the HP concentration. Meanwhile, free base tetraphenylporphyrin (TPP) with no hydroxyl groups were almost not incorporated into the silica gels. These facts suggested that the interaction between hydroxyl groups of the HP molecules and silica network is considerably strong. The UV-vis characters of HP-introduced materials were almost the same as pure HP molecules. The Beer's plot indicated that the HP molecules in the materials are dispersed.

Journal Article↗
PubMed2005

Serum amyloid A (SAA) concentration varies among rheumatoid arthritis patients estimated by SAA/CRP ratio.

BACKGROUND: C reactive protein (CRP) and serum amyloid A (SAA) are similarly sensitive indicators of inflammation, but discrepancies are recognized in several disease conditions. SAA levels are generally higher and vary more among individuals. The significance of the SAA/CRP ratio was evaluated in the estimation of SAA. METHODS: Sera of out-patients with rheumatoid arthritis (RA) and healthy subjects were measured for CRP and SAA cross-sectionally and longitudinally by a highly sensitive latex agglutination turbidimetric immunoassay. The results were classified into four groups according to the CRP concentration, and the SAA/CRP ratios were calculated and evaluated. RESULTS: In the cross-sectional study, CRP and SAA were shown to correlate significantly in sera of patients with RA, but not in healthy subjects. The SAA/CRP ratios were wide RA patients and tended to decrease in the range and mean values were observed depending on the concentration of CRP. In the longitudinal study, variations of the ratio among individuals were wide, but smaller and similar within individuals. The difference in magnitude of the ratios is due to the difference in SAA concentration. CONCLUSION: Variations of SAA/CRP ratios were affected by SAA concentrations. The ratio should be checked in the evaluation of SAA.

Arthritis, Rheumatoid↗
PubMed2005

Correlation between serum levels of free light chain and phenotype of plasma cells in bone marrow in primary AL amyloidosis.

To investigate whether there is a correlation between subtypes of plasma cells in the bone marrow and the production of M-protein, flow cytometry and serum free light chain (FLC) analyses were carried out in 17 patients with primary systemic AL amyloidosis (mean age, 59.9+/-8.8 years) and controls with M-protein (MGUS controls, n=6) and without it (negative controls, n=9). The patients showed a significantly higher value in the serum predominant FLC:serum creatinine ratio (43.8+/-63.2) and CD38++ CD19- CD56+ subpopulation (monoclonal plasma cells) (2.57+/-5.35%) than either the negative (p<0.0005 and p<0.001, respectively) or MGUS controls (p<0.05). With respect to maturation of plasma cells in the bone marrow, the intermediate (MPC-1+ CD45- CD49e-) and mature (MPC-1+ CD45+ CD49e-) subtypes were significantly higher (49.2+/-23.2%, p<0.005) and lower (27.6+/-21.3%, p<0.005) in the patients than in the negative controls, respectively. The serum predominant FLC:serum creatinine ratio was elevated in parallel with an increase in CD38++ CD19- CD56+ and MPC-1+ CD45- CD49e- cells and a decrease in mature subtypes (MPC-1+ CD45+ CD49e- and MPC-1+ CD45+ CD49e+ cells), There was a significantly positive correlation between the serum predominant FLC:serum creatinine ratio and either CD38++ CD19- CD56+ (r=0.510, p<0.05) or MPC-1+ CD45- CD49e- cells (r=0.481, p<0.05). In primary AL amyloidosis M-protein is probably produced by increased monoclonal plasma cells in the bone marrow, particularly by the intermediate subpopulation with a phenotype of MPC-1+ CD45- CD49e-.

Adult↗
PubMed2005

Serum levels of free light chain before and after chemotherapy in primary systemic AL amyloidosis.

OBJECTIVE: Immunoglobulin-related free light chains (FLCs) in serum have recently become quantitatively detectable using the nephelometric assay in plasma cell disorders, including multiple myeloma and AL amyloidosis. To investigate whether FLCs are useful as a diagnostic and therapeutic marker in Japanese patients with primary systemic AL amyloidosis, we determined these values in serum before and after chemotherapy. PATIENTS AND METHODS: The serum FLC analysis was carried out in 25 patients with primary systemic AL amyloidosis (mean age, 60.1+/-8.4 years). All of the patients were shown to have either ALkappa- or ALlambda-immunoreactive amyloid deposits on biopsied tissues. Thirteen patients were treated with VAD (vincristine, doxorubicin and dexamethasone) alone (n=6) or VAD and subsequent high-dose melphalan followed by autologous stem cell support (n=7), and serum FLCs were serially determined before and after the chemotherapy. RESULTS: Before chemotherapy the amyloidogenic FLC was elevated in serum with or without abnormal e/e ratios in 24 patients, including 5 with undetectable M-protein in both serum and urine on immunofixation. After chemotherapy the amyloidogenic FLC in serum was significantly decreased irrespective of high-dose melphalan (p<0.05), and all the patients with normalized kappa/lambda ratios showed a good prognosis. CONCLUSIONS: With respect to sensitivity and quantification serum FLCs will be a key marker for diagnosis and therapeutic effects in primary systemic AL amyloidosis. The prognosis of patients with this disease may be improved if the kappa/lambda ratio in serum can be normalized by intensive chemotherapy.

Adult↗
PubMed2005

[Inflammatory markers; C-reactive protein (CRP) and serum amyloid A (SAA)].

C-reactive protein (CRP) and serum amyloid A (SAA) are sensitive acute phase reactants. Both, but predominantly CRP in Japan, have long been used for monitoring inflammatory diseases. During the recent wave of measuring both at low concentration ranges and utilizing these values to clarity certain disorders involving low grade inflammation, we need to remain aware of factors other than apparent inflammation that can influence these values. These include age, obesity, hyperlipidemia, glucose intolerance, silent atherosclerosis, and therapeutic use of hypolipidemic agents or glucocorticoid. Genetic polymorphism may also be an influence; especially an allelic variant of SAA1 has been proposed to have a positive effect on SAA concentrations. Understanding this, these values should not be evaluated at a single sampling point but used kinetically in the individual.

Acute-Phase Proteins↗
PubMed2005

Classification of neural differentiation-associated genes in P19 embryonal carcinoma cells by their expression patterns induced after cell aggregation and/or retinoic acid treatment.

Expression of neural differentiation-associated genes was examined by RT-PCR and macroarray analyses during neural differentiation of P19 embryonal carcinoma cells induced by cell aggregation and/or retinoic acid (RA) treatment. Results revealed that the neural genes examined could be classified into 4 groups based on their expression patterns. The 1st group included the Wnt-1, Id-1, Id-3 and cdc42 genes, expression of which was altered by cell aggregation alone, but not by RA treatment alone. The 2nd group included the alphaN-catenin, Neuro D and GDNFRbeta genes, expression of which was altered by RA treatment alone, but not by cell aggregation. The 3rd group consisted of the Brn-2, TrkA, bcl-X, N-cadherin, E-cadherin and Otx-2 genes, expression of which was altered by either treatment. The 4th group included the ACTH, D4DR, NGC and Oct-3 genes, the expression of which changed only when both treatments were applied simultaneously. Expression of the Ets-1 and Fli-1 transcription factor genes was up-regulated by either treatment alone at initial stages of neural differentiation of P19 cells, although overexpression of these genes alone could not induce cell differentiation. Our results suggest that although both treatments are required for complete neural differentiation of P19 cells, cell aggregation or RA treatment alone drive differentiation to a certain extent at the gene expression level.

Animals↗
PubMed2004

Effects of PU.1-induced mouse calcium-calmodulin-dependent kinase I-like kinase (CKLiK) on apoptosis of murine erythroleukemia cells.

PU.1, a hematopoietic cell-specific Ets family transcription factor, is involved in the generation of murine erythroleukemia (MEL). To identify the target gene(s) of PU.1 in MEL cells, we carried out differential display (DD) analysis and isolated a novel gene whose expression was up-regulated after overexpression of PU.1 in MEL cells. Because the gene exhibited about 90% homology with the human calcium-calmodulin-dependent kinase I-like kinase (CKLiK) gene, it was identified as a mouse homologue of human CKLiK. The mCKLiK gene was mapped to the mouse chromosome 2A1-A3 region and shown to be expressed predominantly in T cells lymphoma and embryonal carcinoma cell lines and primary thymus and brain. Two types of transcripts were present showing a difference in the 3' portion of the coding region and CREB-activating ability. Overexpression of each isoform of mCKLiK in MEL cells revealed that one of them induces, while the other inhibits apoptosis under low serum condition. Differentiation inhibition and lineage switch to myelomonocytes, which were previously observed in MEL cells overexpressing PU.1, were not provoked in the cells overexpressing mCKLiK. These results suggest that mCKLiK is up-regulated by PU.1 in MEL cells and involved in apoptosis of the cells.

Amino Acid Sequence↗
PubMed2004

A case of primary immunoglobulin light chain amyloidosis with a delayed appearance of Bence Jones protein in urine.

We report here a case of a 58-year-old man who had nephrotic syndrome and immunoglobulin light chain (AL) amyloidosis. This patient underwent a renal biopsy to confirm the diagnosis. Treatment with permanganate before Congo red staining showed systemic secondary amyloidosis (AA) fibrils, which were sensitive to permanganate oxidation. Although this patient was initially diagnosed as having AA amyloidosis, he did not have any chronic inflammatory disease and/or malignancy. The level of amyloid A protein (7.9 microg/mL) in sera was within the normal range (0-8.0 microg/mL). Therefore, we performed an immunostaining of the precursor protein (amino terminus of constant region: kappa and lambda light chains, and AA protein) using duodenal biopsy specimens for a precise diagnosis. Immunostaining was positive for the amino terminus of constant region of the lambda light chain, and negative for the amino terminus of constant region of the kappa light chain and AA protein. No plasma cell proliferation in the bone marrow was observed. We finally diagnosed this patient as having primary AL amyloidosis. It appears that a pathological diagnosis must be performed by immunostaining the precursor proteins with the permanganate digestion technique in tissue of patients with amyloidosis. There were no abnormalities in serum and urine immunoelectrophoresis at the time of renal biopsy in this patient. During the follow-up period, after discharge, Bence Jones protein appeared in the urine, but not in the serum. It is necessary to observe patients with primary AL amyloidosis carefully to determine if they their condition will progress to multiple myeloma.

Amyloidosis↗
PubMed2003

Direct association between PU.1 and MeCP2 that recruits mSin3A-HDAC complex for PU.1-mediated transcriptional repression.

PU.1, a member of the Ets family of transcription factors, is implicated in hematopoietic cell differentiation through its interactions with other transcriptional factors and cofactors. To identify a novel protein(s) binding to PU.1, we carried out affinity purification using a column of Glutathione-Sepharose beads bound to GST-PU.1 fusion protein and isolated several individual proteins using murine erythroleukemia (MEL) cell extracts. Sequence analysis of these proteins revealed that one was MeCP2 a methyl CpG binding protein. GST-pull-down assay and immunoprecipitation assay showed that PU.1 bound directly to MeCP2 via its Ets domain and MeCP2 bound to PU.1 via either its amino terminal domain or trans-repression domain. MeCP2 repressed transcriptional activity of PU.1 on a reporter construct with trimerized PU.1 binding sites. This downregulation was recovered in the presence of histone deacetylase inhibitor, trichostatin A (TSA). MeCP2 was integrated in PU.1-mSin3A-HDAC complex but not in PU.1-CBP complex. Chromatin immunoprecipitation (ChIP) assays showed that PU.1 and MeCP2 were collocated at the PU.1 binding site on the reporter construct and the PU.1 binding site of the intervening sequence 2 (IVS2) region in the intron of the beta-globin gene, which has been proposed to regulate expression of the gene, in undifferentiated MEL cells. The complex disappeared from the region during the course of erythroid differentiation of MEL cells. Our results suggest that MeCP2 acts as a corepressor of PU.1 probably due to facilitating complex formation with mSin3A and HDACs.

Cell Differentiation↗