151
|
Yoshioka K, Ohashi Y, Sakai T, Ito H, Yoshikawa N, Nakamura H, Tanizawa T, Wada H, Maki S. A multicenter trial of mizoribine compared with placebo in children with frequently relapsing nephrotic syndrome. Kidney Int 2000; 58:317-24. [PMID: 10886577 DOI: 10.1046/j.1523-1755.2000.00168.x] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The use of corticosteroids or cytotoxic/immunosuppressive agents such as cyclophosphamide, chlorambucil, and cyclosporine for the treatment of frequently relapsing nephrotic syndrome (FRNS) is limited because of their adverse effects. This study was conducted to evaluate the efficacy and safety of mizoribine, a relatively new immunosuppressive drug developed in Japan, in children with FRNS. METHODS A double-blind, placebo-controlled, multicenter trial was carried out in children, from 2 to 19 years old, with FRNS. At relapse, patients were treated with prednisolone. According to a dynamic allocation, mizoribine or a placebo was concurrently administered to each patient. Prednisolone was gradually tapered and discontinued within 12 weeks. The test drug was maintained for 48 weeks. The primary end point was the relapse rate (the total number of relapses/the total treatment days for all patients). Analyses were performed according to the intention-to-treat principle. RESULTS The primary analysis was conducted on 99 mizoribine- and 98 placebo-treated patients. The relapse rate was lower in the mizoribine group than in the placebo group (0.0055 vs. 0.0067; ratio 0.81, 95% CI, 0.61 to 1.05, P = 0.12). The hazard ratio of the cumulative remission rate between the two groups was 0.79 (95% CI, 0. 57 to 1.08). In the subgroups consisting of patients 10 years old or younger, the relapse rate ratio between the mizoribine subgroup (54 patients) and the placebo subgroup (57 patients) was 0.66 (95% CI, 0. 44 to 0.94, P = 0.017). The hazard ratio of the cumulative remission rate between the two subgroups was 0.56 (95% CI, 0.37 to 0.85, P = 0. 007). Hyperuricemia was the most common adverse event with mizoribine (16%), but was transient. CONCLUSIONS Compared with the placebo, mizoribine significantly decreased the relapse rate and prolonged the remission period in the subgroup consisting of patients 10 years old or younger. This drug may be useful in young children with FRNS who generally relapse more frequently than older children.
Collapse
|
152
|
Ogura Y, Suzuki S, Shirakawa T, Masuda M, Nakamura H, Iijima K, Yoshikawa N. Haemophilus parainfluenzae antigen and antibody in children with IgA nephropathy and Henoch-Schönlein nephritis. Am J Kidney Dis 2000; 36:47-52. [PMID: 10873871 DOI: 10.1053/ajkd.2000.8264] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Although the pathogenesis of immunoglobulin A (IgA) nephropathy and Henoch-Schönlein nephritis (HSN) remains uncertain, there is substantial evidence that they are immune complex-mediated diseases. Recently, Haemophilus parainfluenzae antigens were shown in the glomerular mesangium of adult patients with IgA nephropathy, and greater levels of IgA antibody against H parainfluenzae were also shown in the sera of adult patients with IgA nephropathy. The present study was performed to detect H parainfluenzae antigens and antibody against H parainfluenzae in children with IgA nephropathy and HSN. H parainfluenzae antigens in the mesangium were examined by indirect immunofluorescence, and antibody against H parainfluenzae was examined by enzyme-linked immunosorbent assay. Diffuse global staining of the mesangium with rabbit antisera against H parainfluenzae was shown in 10 of the 32 patients (31%) with IgA nephropathy and 12 of the 34 patients (35%) with HSN. Conversely, only 2 of the 47 patients (4%) with other renal diseases showed staining of glomeruli with rabbit antisera against H parainfluenzae (IgA nephropathy versus other renal diseases, P = 0.003; HSN versus other renal diseases, P = 0.0006). Patients with IgA nephropathy and those with HSN showed significantly greater levels of plasma IgA1 antibody against H parainfluenzae than patients with other renal diseases (IgA nephropathy versus other renal diseases, P = 0.008; HSN versus other renal diseases, P = 0.025). These findings suggest that H parainfluenzae has a role in the cause of these two conditions in a subset of patients.
Collapse
|
153
|
Xu H, Iijima K, Shirakawa T, Shiozawa S, Miwa M, Yamaoka K, Kawamura N, Nakamura H, Yoshikawa N. Platelet-activating factor acetylhydrolase gene mutation in Japanese children with Escherichia coli O157-associated hemolytic uremic syndrome. Am J Kidney Dis 2000; 36:42-6. [PMID: 10873870 DOI: 10.1053/ajkd.2000.8262] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Platelet-activating factor (PAF) may be involved in the pathogenesis of Escherichia coli O157-associated hemolytic uremic syndrome (HUS). PAF is degraded to inactive products by PAF acetylhydrolase. In this study, we investigated whether a PAF acetylhydrolase gene mutation (G-->T transversion at position 994) is involved in HUS in Japanese children. A point mutation in the PAF acetylhydrolase gene (G994T) was identified using polymerase chain reaction in 50 Japanese children with E coli O157-associated HUS and 100 healthy Japanese. We then determined the relationship between the PAF acetylhydrolase G994T gene mutation and clinical features of HUS. There was no difference in genotype and allele frequencies between patients with HUS and healthy controls. The mean duration of oligoanuria was significantly longer in patients with the GT genotype than in those with the GG genotype (P = 0.012). Although 11 of 15 patients (73%) heterozygous for the mutant allele (GT) required dialysis, only 13 of the 35 wild-type homozygotes (GG; 37%) required dialysis (P = 0. 030). Mean plasma PAF acetylhydrolase activity was significantly less in patients with the GT genotype than in those with the GG genotype (P < 0.0001). In conclusion, we have shown an association between the G994T PAF acetylhydrolase gene mutation and the severity of renal damage in E coli O157-associated HUS. Our study suggests that analysis of the PAF acetylhydrolase gene mutation in Japanese children with E coli O157-associated HUS may allow the prediction of the severity of HUS.
Collapse
|
154
|
Tanaka R, Iijima K, Nakamura H, Yoshikawa N. Genetics of immunoglobulin A nephropathy. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2000; 29:364-9. [PMID: 10976391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
INTRODUCTION Immunoglobulin (Ig) A nephropathy is the most common primary glomerulonephritis in the world and about 20% to 50% of patients with it develop progressive renal failure. There is considerable evidence to show that IgA nephropathy is influenced by genetic factors. The purpose of this review is to provide useful information concerning genetics of IgA nephropathy. METHODS AND RESULTS Epidemiological, familial clustering, human leukocyte antigen and IgA immune system (immunoglobulin class switch gene, I alpha 1 germ-line transcript regulatory region gene) studies have led to the hypothesis of genetic susceptibility to IgA nephropathy. Moreover, research on renin angiotensin system, platelet activating factor acetylhydrolase, neuropeptide Y Y1 receptor and others genes has demonstrated that genetic factors influence the pathological severity and natural course of IgA nephropathy. CONCLUSIONS The evidence presented in this review strongly supports the role of genetic factors in IgA nephropathy. Detection of genetic risk factors for IgA nephropathy will allow us to study further the pathogenesis of IgA nephropathy and devise effective therapy.
Collapse
|
155
|
Yoshikawa N, Gotoh S, Umezawa M, Satoh N, Satoh H, Takahashi T, Ito T, Yoshida K. Transgenic Nicotiana occidentalis Plants Expressing the 50-kDa Protein of Apple chlorotic leaf spot virus Display Increased Susceptibility to Homologous Virus, but Strong Resistance to Grapevine berry inner necrosis virus. PHYTOPATHOLOGY 2000; 90:311-316. [PMID: 18944625 DOI: 10.1094/phyto.2000.90.3.311] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
ABSTRACT The 50-kDa protein (P50) encoded by the open reading frame 2 of Apple chlorotic leaf spot virus (ACLSV), a putative movement protein, was expressed in transgenic Nicotiana occidentalis plants. P50 in transgenic plants was mainly detected in a modified form in the cell wall fraction, similar to that in infected leaves. The P50-expressing plants (P50 plants) complemented the systemic spread of the P50-defective mutants of an infectious cDNA clone of ACLSV (pCLSF), indicating that P50 in transgenic plants was functional. Severity of symptoms was greatly enhanced and accumulation of virus in upper leaves was increased in P50 plants inoculated with pCLSF or ACLSV compared with that in nontransgenic control plants (NT plants). Conversely, transgenic plants expressing the coat protein of ACLSV (CP plants) showed a significant delay in symptom development and a reduction of virus accumulation. However, most P50 plants inoculated with Grapevine berry inner necrosis virus (GINV), another species of the genus Trichovirus, neither developed obvious symptoms nor supported virus accumulation in inoculated or upper leaves. In contrast, systemic symptoms developed and virus accumulated equally in NT and CP plants inoculated with GINV. After inoculation with Apple stem grooving virus or Apple stem pitting virus, there was no difference in symptom development and virus accumulation among P50, CP, and NT plants. Our results indicate that transgenic plants expressing a functional P50 were more susceptible to homologous virus and, on the contrary, showed strong resistance to the heterologous virus GINV.
Collapse
|
156
|
Li C, Yoshikawa N, Takahashi T, Ito T, Yoshida K, Koganezawa H. Nucleotide sequence and genome organization of apple latent spherical virus: a new virus classified into the family Comoviridae. J Gen Virol 2000; 81:541-7. [PMID: 10644854 DOI: 10.1099/0022-1317-81-2-541] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A virus with isometric virus particles (ca. 25 nm) was isolated from an apple tree and named Apple latent spherical virus (ALSV). Virus particles purified from infected Chenopodium quinoa formed two bands with densities of 1.41 and 1.43 g/cm(3) in CsCl equilibrium density-gradient centrifugation, indicating that the virus is composed of two components. The virus had two ssRNA species (RNA1 and RNA2) and three capsid proteins (Vp25, Vp24 and Vp20). The complete nucleotide sequences of RNA1 and RNA2 were determined to be 6815 nt and 3384 nt excluding the 3' poly(A) tail, respectively. RNA1 contains two partially overlapping ORFs encoding polypeptides of molecular mass 23 kDa ('23K'; ORF1) and 235 kDa ('235K'; ORF2); RNA2 has a single ORF encoding a polypeptide of 108 kDa ('108K'). The 235K protein has, in order, consensus motifs of the protease cofactor, the NTP-binding helicase, the cysteine protease and the RNA polymerase, in good agreement with the gene arrangement of viruses in the COMOVIRIDAE: The 108K protein contains an LPL movement protein (MP) motif near the N terminus. Direct sequencing of the N-terminal amino acids of the three capsid proteins showed that Vp25, Vp20 and Vp24 are located in this order in the C-terminal region of the 108K protein. The cleavage sites of the 108K polyprotein were Q/G (MP/Vp25 and Vp25/Vp20) and E/G (Vp20/Vp24). Phylogenetic analysis of the ALSV RNA polymerase domain showed that ALSV falls into a cluster different from the nepo-, como- and fabavirus lineages.
Collapse
|
157
|
Migita K, Tanaka H, Okamoto K, Yoshikawa N, Ichinose Y, Urayama S, Yamasaki S, Ida H, Kawabe Y, Kawakami A, Eguchi K. FK506 augments glucocorticoid-mediated cyclooxygenase-2 down-regulation in human rheumatoid synovial fibroblasts. J Transl Med 2000; 80:135-41. [PMID: 10701683 DOI: 10.1038/labinvest.3780017] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Prostaglandins (PG) formed by cyclooxygenase (COX) enzymes are important mediators of inflammation in rheumatoid arthritis. The contribution of the inducible COX-2 to inflammation in the rheumatoid synovium is well documented. We examined the regulation of COX-2 mRNA and protein expression in response to both glucocorticoids (GC) and FK506 using rheumatoid synovial fibroblasts. Combined treatment of FK506 and a low concentration of dexamethasone (DEX) (10(-9) M) down-regulated synovial COX-2 mRNA and protein expression. In contrast, neither FK506 nor DEX (10(-9) M) alone influenced COX-2 expression. Immunocytochemical studies showed that pretreatment with FK506 enhanced the nuclear translocation of the glucocorticoid receptor (GR) in synovial fibroblasts in the presence of low concentrations of DEX (10(-9) M). Transient transfection experiments showed that treatment of cells with FK506 enhanced the expression of glucocorticoid-responsive gene reporter in the presence of DEX (10(-9) M). NF-kappaB is known to mediate the transcriptional activation of the COX-2 gene. Electrophoretic mobility shift assay demonstrated that DNA-binding activity of NF-KB was suppressed more profoundly by FK506 plus DEX (10(-9) M) treatment with those of DEX (10(-9)M) alone in IL-1beta-stimulated synovial cells. Our results indicated that FK506-induced potentiation of GR-mediated repression of synovial COX-2 gene transcription is the result of increased translocation of GR to the nucleus and subsequent repression of NF-kappaB transactivation. Our results also suggest that FK506 may exert anti-inflammatory effects in the rheumatoid synovium by potentiating GR-mediated signal transduction.
Collapse
|
158
|
Yoshikawa N, Ariyoshi H, Aono Y, Sakon M, Kawasaki T, Monden M. Gradients in cytoplasmic calcium concentration ([Ca2+]i) in migrating human umbilical vein endothelial cells (HUVECs) stimulated by shear-stress. Life Sci 2000; 65:2643-51. [PMID: 10619372 DOI: 10.1016/s0024-3205(99)00533-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Using a parallel-plate flow-chamber and confocal laser scanning microscopy (CLSM), we studied the distribution and temporal changes in intracellular Ca2+ concentration ([Ca2+]i) in migrating HUVECs stimulated by shear-stress. In the presence or absence of ATP, shear-stress (10 dyne/cm2) caused morphological change and migration of individual HUVECs in the random direction. After 120 minute exposure to shear-stress, 70% of the cells migrated in the direction of flow, whereas, as many as 30% of the cells migrated to the upstream against flow. A nonspecific plasma membrane Ca2+ channel blocker, Ni2+, abolished such responses markedly, suggesting that Ca2+ influx may be essential for shear-stress dependent morphological change and migration of HUVECs. Analysis of [Ca2+]i distribution revealed the appearance of localized [Ca2+]i elevation inside lamellipodium formed in the direction of cell migration. The localized rise in [Ca2+]i might be closely related with morphological change to regulate the direction of cell migration induced by shear-stress.
Collapse
|
159
|
Yoshikawa N, Ito H. Long-term prognosis of children with severe IgA nephropathy treated with combined therapy. Nephrology (Carlton) 2000. [DOI: 10.1046/j.1440-1797.1999.00100.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
160
|
Yoshikawa N. [Structure and molecular variability of capillovirus gemones]. Uirusu 1999; 49:147-53. [PMID: 10737112 DOI: 10.2222/jsv.49.147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
161
|
Maekawa K, Yoshikawa N, Du J, Nishida S, Kitasato H, Okamoto K, Tanaka H, Mizushima Y, Kawai S. The molecular mechanism of inhibition of interleukin-1beta-induced cyclooxygenase-2 expression in human synovial cells by Tripterygium wilfordii Hook F extract. Inflamm Res 1999; 48:575-81. [PMID: 10598013 DOI: 10.1007/s000110050506] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE Several extracts of Tripterygium wilfordii Hook F (TWHF) have been reported to be effective in patients with rheumatoid arthritis. We investigated the effect of multi-glycosides ofTWHF (GTW), a TWHF extract, on interleukin (IL)-1beta stimulated human rheumatoid synovial cells. MATERIALS AND METHODS IL-1beta-stimulated synovial cells were used to detect the effects of GTW on cyclooxygenase (COX)-1 and COX-2 activities, expression of COX protein and mRNA, and nuclear transcription factors in experiments using respective reporter plasmids. RESULTS GTW inhibited prostaglandin E2 production by IL-1beta-stimulated synovial cells in a concentration-dependent manner, and also inhibited COX-2 protein and mRNA expression in a similar fashion to dexamethasone. However, GTW did not act as a glucocorticoid agonist. GTW repressed IL-1beta-induced nuclear factor-kappaB activity, but did not have a significant influence on activating protein-1 activity. CONCLUSION The anti-rheumatic effect of GTW or TWHF may be partly mediated through the inhibition of prostaglandin E2 production in human synovial cells due to suppression of COX-2 mRNA, possibly via inhibition of nuclear factor-kappaB activity.
Collapse
|
162
|
Inoue Y, Nishio H, Shirakawa T, Nakanishi K, Nakamura H, Sumino K, Nishiyama K, Iijima K, Yoshikawa N. Detection of mutations in the COL4A5 gene in over 90% of male patients with X-linked Alport's syndrome by RT-PCR and direct sequencing. Am J Kidney Dis 1999; 34:854-62. [PMID: 10561141 DOI: 10.1016/s0272-6386(99)70042-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
X-linked Alport's syndrome is caused by mutations in the COL4A5 gene encoding the type IV collagen alpha5 chain (alpha5[IV]). Polymerase chain reaction-single-str and conformation polymorphism (PCR-SSCP) on genomic DNA has previously been used to screen for mutations in the COL4A5 gene, but this method was relatively insensitive, with mutations detected in less than 50% of patients. Here, we report a systematic analysis of the entire coding region of the COL4A5 gene, using nested reverse-transcription-polymerase chain reaction (RT-PCR) and the direct sequence method using leukocytes. This study examines twenty-two unrelated Japanese patients with X-linked Alport's syndrome showing abnormal expression of alpha5(IV) in the glomerular or epidermal basement membranes. Mutations that were predicted to be pathogenic were identified in 12 of the 13 male patients (92%) and five of the nine female patients (56%). Six patients had missense mutations, four had out-of-frame deletion mutations, three had nonsense mutations, and three had mutations causing exon loss of the transcript. The current study shows that nested RT-PCR and the direct sequence method using leukocytes are highly sensitive and offer a useful approach for systematic gene analysis in patients with X-linked Alport's syndrome.
Collapse
|
163
|
Yoshikawa N, Yamamura F, Akita Y, Sato T, Mitamura K. Gastrointestinal lesions in an adult patient with Henoch-Schönlein purpura. HEPATO-GASTROENTEROLOGY 1999; 46:2823-4. [PMID: 10576353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
A 28 year-old man was admitted because drug toxication, due to a high dose of antipsychotic drugs, presented purpuric rash on both legs, lower abdominal pain, arthralgia, and fresh-bloody stool. Colonoscopy observed numerous small ring-like petechiae in the rectum and in the sigmoid colon. Upper gastrointestinal endoscopy found a few petechiae in the antrum of the stomach and in the duodenal second portion. He was treated with coagulation factor X III after admission. After 38 days, there was no abnormal mucosa in the colorectum, the duodenal second portion, or the antrum of the stomach. The disappearance of gastrointestinal lesions correlated with the course of the illness. Gastrointestinal tracts should be thoroughly observed in patients with Henoch-Schönlein purpura.
Collapse
|
164
|
|
165
|
Yamamura F, Yoshikawa N, Akita Y, Mitamura K, Miyasaka N. Relationship between Helicobacter pylori infection and histologic features of gastritis in biopsy specimens in gastroduodenal diseases, including evaluation of diagnosis by polymerase chain reaction assay. J Gastroenterol 1999; 34:461-6. [PMID: 10452678 DOI: 10.1007/s005350050297] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We investigated the relationship between Helicobacter pylori infection and the histologic features of gastritis in gastroduodenal disease, and evaluated the diagnostic usefulness of the polymerase chain reaction (PCR) assay for the detection of H. pylori before and after eradication therapy. Endoscopic biopsy specimens from 81 patients with gastroduodenal disease were examined for the presence of H. pylori by culture and histologic examination. Histologic features of gastritis were classified according to the updated Sydney System, and results of the PCR assay were compared with those of histologic examination, using histologic scores. The density of H. pylori was significantly correlated with polymorphonuclear neutrophil activity and chronic inflammation. These findings suggest that the grades of infiltration of polymorphonuclear neutrophil cells and chronic inflammatory cells correspond to the density of H. pylori infection assessed by the updated Sydney System. Patients with positive results on PCR assay and negative results on histologic examination may have a low density of H. pylori because of severe atrophy in the gastric mucosa. Differences in results for the PCR assay and histologic examination were found in 2 of 12 patients in the detection of H. pylori after eradication therapy. According to the results of the PCR assay and histologic features before and after eradication, the gastric tissue-based PCR assay for H. pylori after eradication may be too sensitive to judge successful eradication of H. pylori.
Collapse
|
166
|
Tanaka R, Iijima K, Xu H, Inoue Y, Murakami R, Shirakawa T, Nishiyama K, Miwa M, Shiozawa S, Nakamura H, Yoshikawa N. Role of platelet-activating factor acetylhydrolase gene mutation in Japanese childhood IgA nephropathy. Am J Kidney Dis 1999; 34:289-95. [PMID: 10430976 DOI: 10.1016/s0272-6386(99)70357-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Platelet-activating factor (PAF) is a potent mediator of inflammatory injury in renal diseases. PAF is degraded to inactive products by PAF acetylhydrolase. Recently, a point mutation (G to T transversion) of the PAF acetylhydrolase gene was observed at position 994, and this mutation was found to contribute to the variability in plasma PAF levels, with undetectable plasma PAF acetylhydrolase activity occurring in homozygous patients (TT genotype) and reduced levels of activity in heterozygous patients (GT genotype). Therefore, we investigated the effect of the PAF acetylhydrolase gene mutation on the pathogenesis and progression of immunoglobulin A (IgA) nephropathy. Genomic DNA was obtained from 89 children with IgA nephropathy and 100 controls. We identified the PAF acetylhydrolase gene mutation (G994T) by polymerase chain reaction. There was no significant difference in genotypic frequency between patients and controls. However, urinary protein excretion at the time of biopsy was significantly greater in patients with the GT/TT genotypes than in those with the GG genotype. The percentage of glomeruli with mesangial cell proliferation was significantly greater in patients with the GT/TT genotypes than in those with the GG genotype. These results indicate the PAF acetylhydrolase gene mutation may influence the degree of proteinuria and the extent of mesangial proliferation in the early stage of childhood IgA nephropathy.
Collapse
|
167
|
Morita S, Sakai T, Okamoto N, Funabiki A, Okada Y, Hasegawa Y, Amano K, Yoshikawa N, Kasuga M. Hemolytic uremic syndrome associated with immunoglobulin A nephropathy: a case report and review of cases of hemolytic uremic syndrome with glomerular disease. Intern Med 1999; 38:495-9. [PMID: 10411356 DOI: 10.2169/internalmedicine.38.495] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A 35-year-old man with immunoglobulin A (IgA) nephropathy who developed hemolytic uremic syndrome (HUS) presented with transient elevation of serum creatinine, thrombocytopenia, and hemolytic anemia with fragmented red cells with nephrotic syndrome. Hemolytic anemia and the temporarily deteriorated renal function were improved after hemodialysis and plasma exchange. Histological findings were consistent with HUS and IgA nephropathy. Including this case, we reviewed the cases of HUS accompanied by glomerular diseases reported from 1969 to 1996. Surprisingly, most cases showed nephrotic syndrome at the onset of HUS. Several possible relationships between HUS and nephrotic syndrome are discussed.
Collapse
|
168
|
López de Saro FJ, Yoshikawa N, Helmann JD. Expression, abundance, and RNA polymerase binding properties of the delta factor of Bacillus subtilis. J Biol Chem 1999; 274:15953-8. [PMID: 10336502 DOI: 10.1074/jbc.274.22.15953] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The delta protein is a dispensable subunit of Bacillus subtilis RNA polymerase (RNAP) that has major effects on the biochemical properties of the purified enzyme. In the presence of delta, RNAP displays an increased specificity of transcription, a decreased affinity for nucleic acids, and an increased efficiency of RNA synthesis because of enhanced recycling. Despite these profound effects, a strain containing a deletion of the delta gene (rpoE) is viable and shows no major alterations in gene expression. Quantitative immunoblotting experiments demonstrate that delta is present in molar excess relative to RNAP in both vegetative cells and spores. Expression of rpoE initiates from a single, sigmaA-dependent promoter and is maximal in transition phase. A rpoE mutant strain has an altered morphology and is delayed in the exit from stationary phase. For biochemical analyses we have created derivatives of delta and sigmaA that can be radiolabeled with protein kinase A. Using electrophoretic mobility shift assays, we demonstrate that delta binds core RNAP with an apparent affinity of 2.5 x 10(6) M-1, but we are unable to demonstrate the formation of a ternary complex containing core enzyme, delta, and sigmaA.
Collapse
|
169
|
Nishikawa M, Takagi T, Yoshikawa N, Shouzu A, Murakami T, Kono M, Owae H, Tanaka K, Iwasaka T, Inada M. Measurement of serum leptin in patients with chronic renal failure on hemodialysis. Clin Nephrol 1999; 51:296-303. [PMID: 10363630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Abstract
BACKGROUND Leptin, the product of the obese gene, is produced exclusively in fat cells. SUBJECTS, MATERIALS AND METHODS To evaluate the clinical significance of measuring serum leptin in 56 patients with chronic renal failure on hemodialysis (HD), we measured leptin levels using radioimmunoassay in 34 normal volunteers and in 56 patients on HD. RESULTS Normal serum leptin averaged 5.7 +/- 0.7 (mean +/- SEM) ng/ml, which correlated significantly (p < 0.001) with the body fat percentage as measured by bioelectrical impedance analysis. Serum leptin in HD patients ranged from 1.3 to 142 ng/ml. The mean serum leptin analyzed after the logarithmic conversion was 5.6 ng/ml, which was not significantly different from the normal control value, although the body fat percentage was significantly lower than normal volunteers. There was a significant (p < 0.01) positive correlation between body fat percentage and serum leptin in both normal controls and HD patients. The slope of the regression curve was steeper in HD patients than in normal controls. CONCLUSION (1) serum leptin levels to body fat mass are significantly higher in HD patients than controls; (2) the variability is much wider in HD patients; and (3) a significant relation exists between percent body fat and log serum leptin, the relation being steeper in HD patients than in controls.
Collapse
|
170
|
Yoshikawa N, Ito H. Combined therapy with prednisolone, azathioprine, heparin-warfarin, and dipyridamole for paediatric patients with severe IgA nephropathy--is it relevant for adult patients? Nephrol Dial Transplant 1999; 14:1097-9. [PMID: 10344344 DOI: 10.1093/ndt/14.5.1097] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
171
|
Fujisawa M, Ono H, Isotani S, Higuchi A, Iijima K, Yoshiya K, Arakawa S, Matsumoto O, Nakamura H, Kamidono S, Yoshikawa N. Significance of chronic transplant nephropathy on early protocol biopsies for graft outcome in pediatric renal transplantation. Transplant Proc 1999; 31:1687-90. [PMID: 10331040 DOI: 10.1016/s0041-1345(99)00065-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
|
172
|
Okamoto K, Tanaka H, Ogawa H, Makino Y, Eguchi H, Hayashi S, Yoshikawa N, Poellinger L, Umesono K, Makino I. Redox-dependent regulation of nuclear import of the glucocorticoid receptor. J Biol Chem 1999; 274:10363-71. [PMID: 10187825 DOI: 10.1074/jbc.274.15.10363] [Citation(s) in RCA: 138] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
A number of transcription factors including the glucocorticoid receptor (GR) are regulated in a redox-dependent fashion. We have previously reported that the functional activity of the GR is suppressed under oxidative conditions and restored in the presence of reducing reagents. In the present study, we have used a chimeric human GR fused to the Aequorea green fluorescent protein and demonstrated that both ligand-dependent and -independent nuclear translocation of the GR is impaired under oxidative conditions in living cells. Substitution of Cys-481 for Ser within NL1 of the human GR resulted in reduction of sensitivity to oxidative treatment, strongly indicating that Cys-481 is one of the target amino acids for redox regulation of the receptor. Taken together, we may conclude that redox-dependent regulation of nuclear translocation of the GR constitutes an important mechanism for modulation of glucocorticoid-dependent signal transduction.
Collapse
|
173
|
Magome H, Yoshikawa N, Takahashi T. Single-strand conformation polymorphism analysis of apple stem grooving capillovirus sequence variants. PHYTOPATHOLOGY 1999; 89:136-40. [PMID: 18944787 DOI: 10.1094/phyto.1999.89.2.136] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
ABSTRACT In an earlier study, we demonstrated that isolates of apple stem grooving capillovirus (ASGV) from fruit trees comprise at least two to four sequence variants that differ considerably from each other in nucleotide sequence. In order to characterize the population of sequence variants within a single tree, we applied a combination of an immunocapture reverse transcription-polymerase chain reaction (IC-RT-PCR) and a single-strand conformation polymorphism (SSCP) analysis of a nested asymmetric PCR product. In the SSCP analysis of the PCR products from ASGV-infected apple, Japanese pear, or European pear trees, two to four bands were detected in samples from all trees, indicating that ASGV exists as a mixture of sequence variants. The composition of sequence variants (the number of bands and their relative quantity) differed among leaf samples from different branches, showing that each sequence variant is distributed unevenly within an individual tree. The SSCP analysis of isolates after serial passage in Chenopodium quinoa plants indicated that passages changed the composition of sequence variants originally contained in ASGV isolates; i.e., some sequence variants dominated and others decreased to undetectable levels.
Collapse
|
174
|
Makino Y, Yoshikawa N, Okamoto K, Hirota K, Yodoi J, Makino I, Tanaka H. Direct association with thioredoxin allows redox regulation of glucocorticoid receptor function. J Biol Chem 1999; 274:3182-8. [PMID: 9915858 DOI: 10.1074/jbc.274.5.3182] [Citation(s) in RCA: 152] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The glucocorticoid receptor (GR) is considered to belong to a class of transcription factors, the functions of which are exposed to redox regulation. We have recently demonstrated that thioredoxin (TRX), a cellular reducing catalyst, plays an important role in restoration of GR function in vivo under oxidative conditions. Although both the ligand binding domain and other domains of the GR have been suggested to be modulated by TRX, the molecular mechanism of the interaction is largely unknown. In the present study, we hypothesized that the DNA binding domain (DBD) of the GR, which is highly conserved among the nuclear receptors, is also responsible for communication with TRX in vivo. Mammalian two-hybrid assay and glutathione S-transferase pull-down assay revealed the direct association between TRX and the GR DBD. Moreover, analysis of subcellular localization of TRX and the chimeric protein harboring herpes simplex viral protein 16 transactivation domain and the GR DBD indicated that the interaction might take place in the nucleus under oxidative conditions. Together these observations indicate that TRX, via a direct association with the conserved DBD motif, may represent a key mediator operating in interplay between cellular redox signaling and nuclear receptor-mediated signal transduction.
Collapse
|
175
|
Tanaka H, Makino Y, Okamoto K, Iida T, Yan K, Yoshikawa N. Redox regulation of the glucocorticoid receptor. Antioxid Redox Signal 1999; 1:403-23. [PMID: 11233142 DOI: 10.1089/ars.1999.1.4-403] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Redox regulation is currently considered as a mode of signal transduction for coordinated regulation of a variety of cellular processes. The transcriptional regulation of gene expression is also influenced by cellular redox state, most possibly through the oxido-reductive modification of transcription factors. The glucocorticoid receptor belongs to a nuclear receptor superfamily and acts as a ligand-dependent transcription factor. We demonstrate that the glucocorticoid receptor function is regulated via redox-dependent mechanisms at multiple levels. Moreover, it is suggested that redox regulation of the receptor function is one of dynamic cellular responses to environmental stimuli and plays an important role in orchestrated crosstalk between central and peripheral stress responses.
Collapse
|