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H Wakui

Publications and source records attributed to H Wakui.

At least 37 records · Page 2Linked to original sources
PubMed1999

Intracellular localization of HSP73 and HSP90 in rat kidneys with acute lysosomal thesaurismosis.

We previously reported that HSP73 and HSP90, major chaperone proteins, accumulated within lysosomes of proximal tubular epithelial cells in rat kidneys with acute gentamicin nephropathy. In this study, we observed serial localization of HSP73 and HSP90 in rat kidneys with acute lysosomal thesaurismosis. Sprague-Dawley rats received poly-D-glutamic acid (PDGA) (250 mg/kg per day) for 3 days, and developed acute lysosomal thesaurismosis of proximal tubular epithelial cells. The intracellular localization of HSP73 and HSP90 was examined by electron microscopy. We also compared the results with those of a non-chaperone protein, a renal isoform of argininosuccinate synthetase, which is an abundant enzyme in proximal tubular epithelial cells. After the PDGA exposure, HSP73 and HSP90 accumulated within enlarged lysosomes of proximal tubular epithelial cells. These accumulations started to appear from day 4 after the first PDGA administration, enlarged in size until day 14, and continued until day 19. Argininosuccinate synthetase also accumulated within the lysosomes, but the magnitude of this lysosomal accumulation was less than those of HSP73 and HSP90. Our findings demonstrated that HSP73 and HSP90 chaperone proteins specifically accumulated within lysosomes of proximal tubular epithelial cells during the course of PDGA-induced acute lysosomal thesaurismosis.

Acetylglucosaminidase↗
PubMed1999

A spectrum of clinicopathological features of nephropathy associated with POEMS syndrome.

BACKGROUND: In POEMS syndrome, substantial involvement of the kidney can occur and is reflected by proteinuria, haematuria, renal dysfunction, and renal failure requiring dialysis therapy. The mechanism by which renal dysfunction is induced and progresses to end-stage renal disease remains obscure. A pathogenic role of cytokines and growth factors has recently been implicated. METHODS: We reviewed cases of 52 Japanese patients with confirmed renal pathology who were reported in the literature, and personally analysed renal tissues from 22 subjects including nine patients of our own. Interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) were measured in our cases. RESULTS: Despite relatively mild renal symptomatology, about half of the cases had azotaemia with creatinine levels above 1.5 mg/dl and the BUN/creatinine ratio markedly raised by volume contraction or wasting. One-tenth of patients were placed on haemodialysis because of advanced or end-stage renal disease. Bilateral and unilateral contracted kidneys were found in four and two cases respectively. Pathological analyses disclosed two major changes: glomerular alterations and endarteritis-like lesions of renal small arteries. The former included glomerular enlargement, cellular proliferation, mesangiolysis and marked swelling of endothelial-mesangial cells. This structural disorganization led to a reduction in renal function to some degree by impairing the glomerular circulation. Vasculopathy of the small artery probably resulted in progressive renal damage and ultimately to kidney contraction. Serum IL-6 was elevated in about 40% of cases. IL-6 levels were found to be high in the ascites of three patients who were examined. In different studies, an increased level of VEGF was found in the peripheral blood (75-100%; overall 92.3%), but no apparent correlation with glomerular alterations was observed. CONCLUSION: POEMS nephropathy can be one cause of end-stage renal disease with variable intrarenal pathological changes of a microangiopathic nature which have differential influences on renal function. A pathogenic role for VEGF in POEMS syndrome appears to be likely, but its causal relation to the nephropathy awaits further investigation.

Adult↗
PubMed1999

Overexpression of the human 72 kDa heat shock protein in renal tubular cells confers resistance against oxidative injury and cisplatin toxicity.

BACKGROUND: Recent studies have shown that the 72-kDa heat shock protein (HSP72) can be induced in renal tubular cells by a variety of stress conditions, and suggested its cytoprotective function. We have tested this hypothesis directly by transfection studies. METHODS: LLC-PK1 cells (porcine renal tubular epithelial cells) were stably transfected with pBK-CMV or pBK-CMV containing the human HSP72 gene (pBK-CMV-HSP72). These cells were then treated with various concentrations of hydrogen peroxide or cisplatin. The cell viability and lytic cell damage were determined by the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay and lactate dehydrogenase release assay. RESULTS: Immunoblot and immunocytochemical analyses showed the high level expression of HSP72 in LLC-PK1 cells transfected with pBK-CMV-HSP72. In addition, the expression of other major HSPs (HSP90, HSP73, HSP60 and HSP27) was not affected by transfection. LLC-PK1 cells overexpressing HSP72 were significantly more resistant to hydrogen peroxide and cisplatin treatments than control cells. CONCLUSION: These results indicate that overexpressed HSP72 plays a direct role in protecting renal tubular cells against oxidative injury and cisplatin toxicity.

Animals↗
PubMed1999

[Goodpasture's syndrome initially presenting with alveolar hemorrhage].

A 17-year-old man was admitted to our hospital because of exertional dyspnea, fever, and hemoptysis. Chest X-ray films disclosed diffuse alveolar infiltrates and patchy shadows in both lungs. Laboratory data included a hemoglobin level of 6.7 g/dl and white blood cell count of 8,100/microliter. Urinalysis revealed microscopic hematuria with RBC cast. Bronchoalveolar lavage fluid from the right middle lobe bronchus was bloody. Anti-GBM antibodies were detected at low levels in serum (10 EU/ml) by ELISA procedures. Renal and lung biopsies were performed. Immunofluorescent studies revealed linear deposits of IgG along glomerular basement membrane of the kidney, but not in alveolar walls of the lung. This case fulfilled the criteria for Goodpasture's syndrome. The patient was treated with methylprednisolone (1,000 mg/day, for 3 days) and plasma exchange (for 2 days), and demonstrated a dramatic improvement in his clinical condition and chest X-ray findings. We were unable to identify autoantibodies to the NC domain of the alpha 3 chain of type IV collagen. Another conformational epitope may play a role in the disease.

Adolescent↗
PubMed1998

Crescentic glomerulonephritis accompanied by myeloperoxidase-antineutrophil cytoplasmic antibodies in a patient having myelodysplastic syndrome with trisomy 7.

A 63-year-old woman developed rapidly progressive glomerulonephritis syndrome with serum myeloperoxidase-anti-neutrophil cytoplasmic antibodies (MPO-ANCA). A renal biopsy showed diffuse crescentic glomerulonephritis. Immunofluorescence and electron microscopic studies showed no significant deposits in the glomeruli. The morphological findings were consistent with pauci-immune type crescentic glomerulonephritis. In addition, the patient had erythropoietin-resistant anemia and subsequent pancytopenia. Bone marrow was normocellular without an excess of blasts. However, multinuclear erythroblasts, hypersegmented neutrophils, and megakaryocytes without platelet formation were observed. Chromosome analysis of the bone marrow showed 47,XX,+7. This is the first case of MPO-ANCA-related crescentic glomerulonephritis in a patient with myelodysplastic syndromes (MDS). A possible relationship between MPO-ANCA and MDS is discussed.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1998

Human parathyroid hormone does not influence human erythropoiesis in vitro.

BACKGROUND: Although renal anaemia is associated with secondary hyperparathyroidism, the relationship of both conditions remains obscure. Previously it was reported that high levels of bovine parathyroid hormone (PTH) did not inhibit in vitro human erythropoiesis, but whether human PTH inhibits in vitro human erythropoiesis has not been determined. METHOD: To clarify the direct effects of human biologically active N-terminal (1-34) PTH and intact (1-84) PTH on human haematopoietic progenitor growth, we investigated colony assays of human erythropoiesis and granulomonopoiesis. RESULTS: Neither N-terminal PTH (300 ng/ml) nor intact PTH (5000 pg/ml) inhibited haematopoietic progenitor growth. CONCLUSION: Our findings confirm that human PTH does not directly inhibit human erythropoiesis.

Animals↗
PubMed1997

Interaction of the ligand-activated glucocorticoid receptor with the 14-3-3 eta protein.

The glucocorticoid receptor (GR) is a ligand-activated transcription factor. In this study, we used the yeast two-hybrid system to isolate cDNAs encoding proteins that interact with the human GR ligand-binding domain (LBD) in a ligand-dependent manner. One isolated cDNA from a HeLa cell library encoded the COOH-terminal portion of the eta-isoform of the 14-3-3 protein (residues 187-246). Glucocorticoid agonists, triamcinolone acetonide and dexamethasone, induced the GR LBD/14-3-3eta protein fragment interaction, but an antagonist, RU486, did not. Glutathione S-transferase pull-down experiments in vitro showed that full-length 14-3-3eta protein also interacted with the activated GR. Transient transfection studies using COS-7 cells revealed a stimulatory effect of 14-3-3eta protein on transcriptional activation by the GR. The 14-3-3 family members have recently been found to associate with a number of important signaling proteins, such as protein kinase C and Raf-1, as functional modulators. Our findings suggest a novel regulatory role of 14-3-3eta protein in GR-mediated signaling pathways and also point to a mechanism whereby GR may cross-talk with other signal transduction systems.

14-3-3 Proteins↗
PubMed1997

Purification and localization of a 25-kD porcine renal puromycin aminonucleoside-binding protein.

BACKGROUND: Reactive oxygen species (ROS) are considered to have a role in the progression of puromycin aminonucleoside (PAN) nephrosis. However, the exact mechanism by which PAN induces ROS in this model is little known. In the present study, we attempted to purify a candidate for the target protein from PAN nephrotoxicity. METHODS: Using PAN-affinity column chromatography, a series of PAN-binding proteins was isolated from porcine renal extracts. We produced a specific antibody against a 25-kD protein eluted from the PAN-affinity matrix, and then developed a method to purify this protein. A partial amino acid sequence of the 25-kD PAN-binding protein was determined, and its tissue distribution was examined by immunoblot and immunohistochemical studies. RESULTS: The purified 25-kD PAN-binding protein was identified as a renal homolog of a new member of NAD(P)H:quinone oxidoreductases (NQOs, EC 1.6.99.2) that suppress the semiquinone and superoxide anion formation in cells, designated NQO2. Immunoblot analysis revealed a higher expression of the 25-kD PAN-binding protein in the kidney, brain, and liver among porcine major organs. Immunohistochemical studies showed an intrarenal distribution of this protein in epithelial cells of the glomeruli and tubules, mesangial cells, and vascular smooth muscle cells. CONCLUSIONS: We have purified the renal homolog of NQO2 as a PAN-binding protein, and shown its unique tissue expression. PAN may bind to the NQO2 homolog and inhibit its function in the renal target cells. This is presumed to result in an increase of ROS in the kidney with PAN nephrosis.

Amino Acid Sequence↗
PubMed1996

Late onset bone marrow transplant nephropathy.

We report a patient who exhibited proteinuria and renal failure 93 months after receiving an allogeneic bone marrow transplantation (BMT) from his HLA-identical brother. A renal biopsy specimen revealed segmental sclerosis, mesangiolysis, subendothelial lucency in the glomeruli, fibrosis and small round cell infiltration in the interstitium, and hyaline droplets in the intimal spaces of arterioles and small arteries. These histological findings were consistent with late onset BMT nephropathy. This nephropathy may represent a more serious problem in the near future in Japan, since the number of BMT performed has been increasing with the establishment of a bone marrow bank.

Adult↗
PubMed1996

Clinicopathological analysis and therapy in hepatitis C virus-associated nephropathy.

We analyzed the clinicopathological features and therapy in 19 patients with kidney disease accompanied by hepatitis C viral infection, including 12 patients with mesangial proliferative glomerulonephritis (including eight with IgA nephropathy), six with membranoproliferative glomerulonephritis (MPGN), and one with membranous nephropathy. Persistent hematuria and/ or proteinuria (10 patients) was the most common finding, followed by nephrotic syndrome (8 patients). Cryoglobulinemia was detected in six of 19 patients examined (four of six patients with MPGN). Analysis of hepatitis C virus (HCV)-RNA genotype in 13 patients revealed that nine of them had type II genotype. All four patients with MPGN, who had serum positive for HCV-RNA, had type II genotype. Five patients were treated with interferon-alpha (IFN-alpha) without a demonstrable effect on renal impairment, whereas five of 11 patients treated with steroids showed improvement of the renal impairment. During the course of steroid therapy, the serum titer of HCV-RNA decreased in 5 of 7 patients. These observations suggest that HCV infection may be associated with several forms of glomerulonephritis. Type II HCV-RNA may have a strong association with MPGN in Japan. Steroid therapy is not contraindicated in patients with HCV-associated nephropathy if they are resistant to IFN-alpha treatment.

Adolescent↗
PubMed1996

Tubulointerstitial nephritis with renal tubular acidosis and asymptomatic primary biliary cirrhosis accompanied by antibody to a 52-kDa mitochondrial protein alone.

We report a patient presenting with a mixed type of renal tubular acidosis, who demonstrated anti-mitochondrial antibodies on immunofluorescent study. However, study of anti-M2 antibody (enzyme immunoassay) was negative. Renal biopsy revealed lymphocyte infiltration in the interstitium compatible with chronic tubulointerstitial nephritis. Liver biopsy demonstrated a mild degree of primary biliary cirrhosis (PBC) but biochemical liver function tests were normal, resulting in a diagnosis of asymptomatic PBC. Using affinity chromatography conjugated with the patient's IgG, we purified a 52-kDa protein from a porcine renal mitochondrial fraction. This protein was identified as a component of a mitochondrial multienzyme complex such as dihydrolipoamide acyltransferase of the branched-chain alpha-keto acid dehydrogenase complex (BCKD), based on the molecular mass analysis and partial amino acid sequence of the purified protein. This is the first report of the detection of antibody to 52-kDa mitochondrial protein alone in a patient who showed predominantly tubulointerstitial damage in the kidney rather than liver damage.

Acidosis, Renal Tubular↗
PubMed1996

[Two cases of malignant lymphoma with initial symptoms like orbital cellulitis and complicated by hemophagocytosis].

We reported 2 patients with malignant lymphoma complicated by hemophagocytic syndrome. Their clinical signs at onset were those of orbital cellulitis. Lymphoma complicated with hemophagocytosis is called lymphoma-associated hemophagocytosis syndrome (LAHS) and its prognosis is reported to be very poor. So far as we know, this is the first report in the ophthalmological field. In our patients, we suspected that the lesions occurred from the orbit or skin of this area. The first patient was a 22-year-old man and the second patient a 16-year-old girl. The diagnosis was very difficult at the onset of disease. Within 6 months after the first opthalmological examination, both died. When orbital cellulitis is suspected and antibiotic therapy is ineffective, we should suspect hemophagocytic syndrome (HPS) and should examine serum ferritin which is a good markers of HPS. Early biopsy and consultation with a hematologist are very important.

Adolescent↗
PubMed1995

Mammalian 60-kDa stress protein (chaperonin homolog). Identification, biochemical properties, and localization.

Mammalian chaperonin homolog (HSP60) was purified from porcine livers cytosol using a tandem ATP-Sepharose column and Mono Q column chromatography. A partial amino acid sequence (96 amino acid residues) of this protein was determined and coincided with those of human HSP60 with 96.9% homology, which was deduced from the nucleotide sequence of the cDNA. The sequence of the NH2 termini of the purified protein (5 amino acid residues) coincided with the signal sequence of HSP60. These facts led to the identification of the 60-kDa liver protein with the chaperonin homolog. Dihydrofolate reductase was able to form a stable complex with the liver chaperonin homolog. The liver chaperonin homolog was detected by at least five spots around pI = 5.6 on two-dimensional gel electrophoresis. Immunoblotting studies using an antibody against chaperonin homolog showed that the chaperonin homolog was localized in the cytosol, mitochondrial, and nuclear fractions of porcine liver. The chaperonin homolog was localized both in the mitochondria and cytoplasm of rat kidneys at the electron microscopic level. The chaperonin homolog in the cytosol, but not in the other subcellular fractions, was cross-reacted with an antibody against the synthetic peptide corresponding to the signal peptide of HSP60 as well as the purified chaperonin homolog on immunoblotting. These results suggested that the functional chaperonin homolog in the cytosol may be transported into the mitochondria and the protein may be processed to mitochondrial HSP60 in the organella.

Amino Acid Sequence↗
PubMed1995

A combination of livedo racemosa, occlusion of cerebral blood vessels, and nephropathy: kidney involvement in Sneddon's syndrome.

A 59-year-old woman with retinal vein thrombosis and livedo racemosa had hematuria (4+) and proteinuria (1.7 g/day). Skin biopsy showed swollen blood vessel walls with infiltration of mononuclear cells, which were compatible with livedo racemosa (vasculitis). Magnetic resonance imaging (MRI) of the brain demonstrated multiple lacunar infarctions in the basal ganglia and white matter. Renal biopsy showed that small round cells had infiltrated into the interstitium, and a reticular structure was observed in the glomerular hilus. An amorphous substance composed of a single cell was present in the glomerular capillary lumen. Immunofluorescent study demonstrated the deposition of only IgA, in a segmental pattern differing from the diffuse global mesangial pattern seen in IgA nephropathy. After combined therapy including 40 mg/day prednisolone, 50 mg/day cyclophosphamide, antiplatelet drug, and anticoagulant was started, proteinuria and hematuria improved to 0.5 g/day and 2+, respectively, at the time of discharge. Sneddon's syndrome is a rare entity characterized by livedo racemosa and cerebrovascular lesions. In our patient with livedo racemosa, occlusion of cerebral blood vessels, and nephropathy with segmental immunoglobulin A (IgA) deposition, no antiphospholipid antibodies were detected on routine examination. Dermatologists, neurologists, psychiatrists, and nephrologists should be aware of the existence of Sneddon's syndrome with nephropathy (LI-O-N).

Antibodies, Antiphospholipid↗
PubMed1995

Induction of heat-shock proteins HSP73 and HSP90 in rat kidneys after ischemia.

We examined rat kidneys for serial expressions of two major heat-shock proteins (HSPs), HSP73 and HSP90, after 60 min of unilateral renal ischemia up to day 28. Immunohistochemical studies showed that HSP73 and HSP90 were rapidly induced in the cytoplasm of injured epithelial cells of the S3 segment of proximal tubules and were again induced in the cytoplasm of regenerative cells in this segment from day 3. In epithelial cells of the Henle's loops, HSP90 was also induced in the cytoplasm of both injured and regenerative cells, but HSP73 was not induced in this portion. Furthermore, a transient accumulation of HSP73 into the nucleus was observed in epithelial cells of papillary collecting ducts shortly after ischemia. Serial immunoblot analysis of isotonic buffer extractable fractions from ischemic kidneys revealed the induction of both HSP73 and HSP90 in the degenerative and regenerative phases: the maximal inductions in the two phases were at 3-6 and on days 5-7, respectively. These results demonstrate that HSP73 and HSP90 are induced in injured tubular epithelial cells with a regional heterogeneity during the degenerative and regenerative phases after renal ischemia and suggest that these HSPs are involved in the process of postischemic cellular recovery.

Animals↗