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Shiro Maeda

Publications and source records attributed to Shiro Maeda.

28 records · Page 2Linked to original sources
PubMed2003

Association of single-nucleotide polymorphisms in the polymeric immunoglobulin receptor gene with immunoglobulin A nephropathy (IgAN) in Japanese patients.

Immunoglobulin A nephropathy (IgAN) is a primary glomerulonephritis of common incidence world-wide whose etiology and pathogenesis remain unresolved, although genetic factors are assumed to be involved in the development and progression of this disease. To identify genetic variations that might confer susceptibility to IgAN, we performed a case-control association study involving 389 Japanese IgAN patients and 465 controls. Genome-wide analysis of approximately 80,000 single-nucleotide polymorphisms (SNPs) identified a significant association between IgAN and six SNPs located in the PIGR (polymeric immuoglobulin receptor) gene at chromosome 1q31-q41. One of them, PIGR-17, caused an amino-acid substitution from alanine to valine at codon 580 (chi(2)=13.05, P=0.0003, odds ratio [OR] =1.59, 95% confidence interval [95% CI] =1.24-2.05); the OR of minor homozygotes to others was 2.71 (95% CI=1.31-5.61). Another SNP, PIGR-2, could affect promoter activity (chi(2)=11.95, P=0.00055, OR=1.60, 95% CI=1.22-2.08); the OR of minor homozygotes to others was 2.08 (95% CI=0.94-4.60). Pairwise analyses demonstrated that all six SNPs were in almost complete linkage disequilibrium. Biopsy specimens from IgAN patients were positively stained by antibody against the secretory component of PIGR, but corresponding tissues from non-IgAN patients were not. Our results suggest that a gene associated with susceptibility to IgAN lies within or close to the PIGR gene locus on chromosome 1q in the Japanese population.

Adult↗
PubMed2003

C-106T polymorphism of AKR1B1 is associated with diabetic nephropathy and erythrocyte aldose reductase content in Japanese subjects with type 2 diabetes mellitus.

BACKGROUND: The C-106T polymorphism of AKR1B1, which encodes aldose reductase (AR), was reported to be associated with diabetic nephropathy (DN). However, this association in Japanese patients with type 2 diabetes mellitus and its potential role as a clinical marker remain unclear. METHODS: The C-106T polymorphism was genotyped in 228 cases (microalbuminuria or overt proteinuria) and 220 controls (normoalbuminuria with diabetes duration > or =10 years) for a case-control comparison, and the association with erythrocyte AR content was investigated. In addition, a new C-11G polymorphism in the promoter region of AKR1B1 was genotyped. RESULTS: The distribution of genotypes of the C-106T polymorphism in cases was significantly different from that in controls (P = 0.031). Carriers of the TT genotype at the C-106T polymorphism were more frequent in cases than controls, with an odds ratio of 4.7 (95% confidence interval, 1.3 to 17). Erythrocyte AR content was significantly elevated in TT carriers in comparison to non-TT carriers (13.1 +/- 1.2 versus 10.2 +/- 1.2 ng/mg hemoglobin [Hb]; P < 0.001) and in cases in comparison to controls (10.6 +/- 1.3 versus 10.1 +/- 1.2 ng/mg Hb; P = 0.041). However, distribution of genotypes of the C-11G polymorphism and estimated frequencies of haplotypes defined by these 2 polymorphisms did not differ between cases and controls. CONCLUSION: The TT genotype of the C-106T polymorphism of AKR1B1 increases the risk for DN in Japanese subjects with type 2 diabetes mellitus, which could be linked in part to greater expression of AR.

Aged↗
PubMed2003

Crystal structure of Diels-Alder cycloadduct formed from 1-(1,2,3-1H-benzotriazol-1-yl)-2-(4-methylphenyl)-2H-isoindole and dimethyl acetylenedicarboxylate.

The structure of the Diels-Alder cycloadduct formed from 2-(1,2,3-1H-benzotriazol-1-yl)-2-(p-tolyl)-2H-isoindole and dimethyl acetylenedicarboxylate was proved as 11-aza-1-(1,2,3-1H-benzotriazol-1-yl)-11-(4-methylphenyl)-tricyclo-[5.2.1.0(2.7)]undeca-2,4,6.9-tetraene-9,10-dioic acid dimethyl ester. The benzotriazole moiety was located as its 1-yl form, analogous to previous reports. The benzotriazole and the benzene (of tricyclo framework) planes were twisted with an angle of 115.83 degrees. Intramolecular close contacts between benzotriazole and ester are characteristic [N(3)...C(26), 2.754(3)A; N(3)...H(22), 3.26(4)A]. The shortest contact of N(3)...H(22) accounting for the rotation of the methyl group is estimated to be 3.10 A, which might be reasonable as C-H...N-type hydrogen bonding.

Journal Article↗
PubMed2003

Association of solute carrier family 12 (sodium/chloride) member 3 with diabetic nephropathy, identified by genome-wide analyses of single nucleotide polymorphisms.

To identify genetic elements that might confer susceptibility to diabetic nephropathy, we performed a genome-wide analysis of gene-based single nucleotide polymorphisms (SNPs) in a large cohort of Japanese patients with diabetes. In case-control association studies, patients with type 2 diabetes were divided into two groups, one having retinopathy as well as overt nephropathy and the other (the control group) having diabetic retinopathy but with no signs of renal involvement. Genotyping of these patients at >55,000 SNP loci indicated a gene encoding solute carrier family 12 member 3 (SLC12A3) to be a good candidate for the susceptibility to diabetic nephropathy, in view of a significant association of one landmark SNP located in the 24th intron (chi(2) = 15.4, P = 0.000087, odds ratio = 2.53 [95% CI 1.57-4.09]). Subsequent analysis of additional genetic variations in this gene identified several SNPs that were significantly associated with nephropathy, especially one in exon 23 (+78 G to A: Arg913Gln, chi(2) = 18.5, P = 0.00002, odds ratio = 2.53 [95% CI 1.64-3.90]). The results implicated that substitution of Arg913 to Gln in the SLC12A3 gene might reduce the risk to develop diabetic nephropathy and suggested that the gene product might be a potential target for the prevention or treatment of this disease.

Age of Onset↗
PubMed2002

Cyclic AMP inhibits stretch-induced overexpression of fibronectin in glomerular mesangial cells.

Glomerular hypertension is proposed to play an important role in the progression of various glomerular diseases. Glomerular mesangial cells are considered to be exposed to the stretch stress due to glomerular hypertension and are found to produce the excess amount of extracellular matrix (ECM) proteins including fibronectin when exposed to the mechanical stretch. Herein, we provide the evidence that cAMP-generating agents inhibit the stretch-induced overexpression of fibronectin through the inhibition of the stretch-induced activation of mitogen-activated protein kinases (MAPKs) in protein kinase-A-dependent manner. We also found that the mechanical stretch enhanced the binding of nuclear extracts to activator protein-1 (AP-1)-like sequences in the promoter region of rat fibronectin gene and this enhancement was also prevented by the cAMP-generating agent. These results indicate that the agents, which activate cAMP/protein kinase-A axis, may work protectively against the injury from glomerular hypertension in mesangial cells.

Animals↗
PubMed2002

Association between single-nucleotide polymorphisms in selectin genes and immunoglobulin A nephropathy.

Although intensive efforts have been undertaken to elucidate the genetic background of immunoglobulin A nephropathy (IgAN), genetic factors associated with the pathogenesis of this disease are still not well understood. We designed a case-control association study that was based on linkage disequilibrium among single-nucleotide polymorphisms (SNPs) in the selectin gene cluster on chromosome 1q24-25, and we found two SNPs in the E-selectin gene (SELE8 and SELE13) and six SNPs in the L-selectin gene (SELL1, SELL4, SELL5, SELL6, SELL10, and SELL11) that were significantly associated with IgAN in Japanese patients. All eight SNPs were in almost complete linkage disequilibrium. SELE8 and SELL10 caused amino acid substitutions from His to Tyr and from Pro to Ser (chi2=9.02, P=.0026, odds ratio = 2.73 [95% confidence interval [CI] 1.38--5.38] for His-to-Tyr substitutions; chi2=17.4, P=.000031, odds ratio = 3.61 [95% CI 1.91--6.83] for Pro-to-Ser substitutions), and SELL1 could affect promoter activity of the L-selectin gene (chi2=19.5, P=.000010, odds ratio = 3.77 [95% CI 2.02--7.05]). The TGT haplotype at these three loci was associated significantly with IgAN (chi2=18.67, P=.000016, odds ratio = 1.88 [95% CI 1.41--2.51]). Our results suggest that these eight SNPs in selectin genes may be useful for screening populations susceptible to the IgAN phenotype that involves interstitial infiltration.

Case-Control Studies↗
PubMed2002

Single-nucleotide polymorphisms in the class II region of the major histocompatibility complex in Japanese patients with immunoglobulin A nephropathy.

Immunoglobulin A nephropathy (IgAN) is a form of chronic glomerulonephritis of unknown etiology and pathogenesis. Immunogenetic studies have not conclusively indicated that human leukocyte antigen (HLA) is involved. As a first step in investigating a possible relationship between HLA class II genes and IgAN, we analyzed the extent of linkage disequilibrium (LD) in this region of chromosome 6p21.3 in a Japanese test population and found extended LD blocks within the class II locus. We designed a case-control association study of single-nucleotide polymorphisms (SNPs) in each of those LD blocks, and determined that SNPs located in the HLA- DRA gene were significantly associated with an increased risk of IgAN ( P = 0.000001, odds ratio = 1.91 [95% confidence interval 1.46-2.49]); SNPs in other LD blocks were not. Our data imply that some haplotype of the HLA- DRA locus has an important role in the development of IgAN in Japanese patients.

Adult↗
PubMed2001

Endothelin-1 induces cyclooxygenase-2 expression via nuclear factor of activated T-cell transcription factor in glomerular mesangial cells.

Nuclear factor of activated T cells (NFAT) originally was identified as a T-cell-specific transcription factor whose activity is regulated by calcineurin, one of the serine-threonine phosphatases. Recent studies have shown that NFAT also is expressed in nonlymphoid cells and plays an important role in various cell functions. It is widely known that treatment with cyclosporin A (CsA), which can inhibit calcineurin/NFAT signaling, results in glomerular dysfunction characterized by a decrease of GFR or glomerulosclerosis, suggesting that NFAT might regulate the glomerular function. However, the precise function of NFAT in glomerular cells remains to be clarified. Herein, evidence has been produced that NFAT2/NFATc, one of five known NFAT isoforms, is expressed in glomerular mesangial cells. Stimulation of mesangial cells with endothelin-1 caused translocation of NFAT2 into the nucleus with a concomitant increase in NFAT2 DNA-binding activity, both of which were inhibited by CsA. Furthermore, CsA inhibited endothelin-1-induced cyclooxygenase-2 (COX-2) expression in mesangial cells. NFAT2 bound directly to the GGAAA sequence, which is the minimal consensus sequence for NFAT binding, in a promoter region of rat COX-2 gene, and it enhanced the reporter activity of rat COX-2 promoter in mesangial cells. These findings provide the first evidence that NFAT2 is expressed and regulates COX-2 gene expression in mesangial cells. These results will contribute to evaluation of the precise roles of NFAT in glomerular functions and the CsA-induced nephrotoxicity.

Animals↗
PubMedDate not supplied

High-performance photoelastic modulator for polarization modulation spectrometer.

A high-performance photoelastic modulator (PEM) has been built. It consists of a home-made PEM head and a home-built PEM driver that is based on the principle of the phase-locked loop (PLL) (PLL PEM driver). It was installed in our new type circular dichroism (CD) spectrometer for visible light region and its performance was evaluated. With the phase angle being set exactly to zero, the PEM is found to be about eight times more efficient than commercially available one. The efficiency of PEM depends not only on the efficiency of PEM driver but also on the quality of PEM head. The latter can be estimated from admittance-parameter measurements without installing it into a spectrometer. With substituting the PLL PEM driver for a conventional one, the PEM drive voltage can be reduced from one-half to one-third and the baseline shift for air blank that is a measure of the total performance of polarization modulation spectrometers becomes quite small.

Journal Article↗