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I Kurihara

Publications and source records attributed to I Kurihara.

At least 19 recordsLinked to original sources
PubMed2004

Ubc9 interacts with chicken ovalbumin upstream promoter-transcription factor I and represses receptor-dependent transcription.

Chicken ovalbumin upstream promoter-transcription factors (COUP-TFs) are orphan receptors involved in regulation of neurogenesis and organogenesis. COUP-TF family members are generally considered to be transcriptional repressors and several mechanisms have been proposed to underlie this activity. To explore novel transcriptional coregulators for COUP-TFs, we used the COUP-TFI as bait in a yeast two-hybrid screen of an adrenocortical adenoma cDNA library. We have identified Ubc9, a class E2 conjugating enzyme of small ubiquitin-related modifier (SUMO)-1 as a COUP-TFI corepressor. Ubc9 interacts with COUP-TFI in yeast and in glutathione S-transferase pulldown and coimmunoprecipitation assays. Fluorescence imaging studies show that both Ubc9 and COUP-TFI are colocalized in the nuclei of transfected COS-1 cells. The C-terminal region of Ubc9 encoding amino acids 59-158 interacts with the C-terminus of COUP-TFI encoding amino acids 383-403, in which transcriptional repression domains are located. Mammalian one-hybrid assays utilizing a variety of Ubc9 fragments fused to Gal4 DNA-binding domain show that a Ubc9 fragment encoding amino acids 1-89 contains autonomous transferrable repression domain. Transfection of Ubc9 into COS-1 cells markedly enhances transcriptional repression by Gal4 DNA-binding domain-fused to COUP-TFI(155-423), but not by Gal4-COUP-TFI(155-388) which lacks a repressor domain. Coexpression of a C-terminal deletion mutant of Ubc9(1-58), which fails to interact with COUP-TFI, but retains a transcriptional repression domain, has no effect on Gal4-COUP-TFI-mediated repression activity. These findings indicate that interaction of Ubc9 with COUP-TFI is crucial for the corepressor function of Ubc9. Overexpression of Ubc9 similarly enhances COUP-TFI-dependent repression of the promoter activity of the bovine CYP17 gene encoding steroid 17alpha-hydroxylase. In addition, the C93S mutant of Ubc9, which abrogates SUMO-1 conjugation activity, continues to function as a COUP-TFI corepressor. Our studies indicate that Ubc9 functions as a novel COUP-TFI corepressor, the function of which is distinct from its SUMO-1 conjugating enzyme activity.

Animals↗
PubMed2000

Risk factors associated with persistent postoperative hypertension in Cushing's syndrome.

The aim of the present study was to assess the long-term results of adrenalectomy and to evaluate potential risk factors for the persistence or recurrence of hypertension. Forty-five patients with Cushing's syndrome caused by benign cortisol-producing adrenocortical adenomas were evaluated before and for a period of 1 year after surgical cure. When the patients were classified into two groups according to whether their preoperative BP was more (HBP group) or less (NBP group) than 140/90 mmHg, the BP level was found to be continuously higher in the HBP group than in the NBP group during the year after surgery. This finding suggests that the preoperative BP level in Cushing's syndrome may be a determinant factor for persistent hypertension after surgery (P<0.05). In addition, a correlation was found between postoperative BP level and duration of hypertension (P<0.05), but no relationships were found between postoperative BP levels and other factors, including age, BMI, tumor size, serum cortisol, aldosterone, potassium, total cholesterol, or glucose levels. The above findings indicate that intensive control of preoperative BP to maintain it below 140/90 mmHg with antihypertensive medication is a very important means of improving prognosis for postoperative BP. Immediate diagnosis and surgical treatment to reduce the duration of hypertension are also crucial for the long-term BP prognosis.

Adrenalectomy↗
PubMed2000

Expression and regulation of BCL-2 family genes in human adrenocortical adenomas in comparison with adrenal hyperplasia of Cushing's disease.

The significance of increases in the expression of apoptosis-suppressing genes such as bcl-2 and mcl-1/EAT in human adrenal tumors has not yet been fully elucidated. Furthermore the roles of these genes in cell proliferation may involve interaction with steroidogenesis in the tumors via intracellular second messengers. Cyclic AMP (cAMP) caused human adrenocortical H295R cells to overexpress hCYP17 resulting in hypersecretion of cortisol. At the same time, however, expression of bcl-2, which has a cAMP response element (CRE), was not affected. Furthermore, in vivo Bcl-2 protein analysis showed its down-regulation in adrenal hyperplasia of Cushing's disease despite ACTH stimulation. Exogenous addition of glucocorticoid did not affect the expression of bcl-2 family genes. Expressions of Mcl-1/EAT and Bax did not differ markedly among human adrenal glands affected by various pathologies. In conclusion the down-regulation of Bcl-2 in Cushing's disease did not agree with no induction of this gene by cAMP in H295R cells, suggesting that expression of Bcl-2 protein was not regulated mainly by cAMP-protein kinase (PKA) pathways in human adrenal hyperplasia.

Adenoma↗
PubMed2000

Transcriptional regulation of steroid receptor coactivator-1 (SRC-1) in glucocorticoid action.

Diverse mechanisms of steroid receptor action have been clarified in recent years, as a consequence of the discovery of multiple coactivators. Among them, steroid receptor coactivator-1 (SRC-1) is a member of the p160 coactivator families, which are 160 kDa proteins that interact with steroid receptors in a hormone-sensitive manner. Since coactivators function as transcriptional power boosters, subtle changes in coactivator expression levels in certain cells markedly change of receptor-mediated transcriptional activity. Expression of the glucocorticoid receptor (GR) has been shown to be autoregulated in glucocorticoid action, i.e., GR is downregulated by its cognate ligand, indicating that this autoregulation of GR may protect target cells against excessive hormone action. In the present study, we examined whether coactivator expression levels are also regulated by glucocorticoids. Among several coactivators, the SRC-1 mRNA level was downregulated by dexamethasone treatment in rat tissues, such as liver, heart, kidney, stomach, and cerebrum, in vivo. We also demonstrated dexamethasone-mediated downregulation of SRC-1 mRNA and its protein levels in rat renal mesangial cells in vitro. These results suggest that ligand-mediated downregulation of SRC-1 is crucial in the physiology of glucocorticoid action.

Animals↗
PubMed2000

Orphan receptors COUP-TF and DAX-1 as targets in disordered CYP17 expression in adrenocortical tumors.

CYP17 gene transcription is activated by SF-1 binding to a cyclic AMP-responsive sequence within the promoter region of the gene, and its transcription is inhibited by COUP-TF binding to the sequence. Another orphan receptor, DAX-1, is shown to act as a suppressor of SF-1-mediated transcription. We examined the expression level of these orphan receptors in adrenocortical tumors and compared the results with CYP17 expression. CYP17 was highly expressed in cortisol-producing adenomas, whereas COUP-TF and DAX-1 expression levels were very low. In deoxycorticosterone-producing adenomas, on the other hand, CYP17 expression was extremely low, whereas DAX-1 was highly expressed and SF-1 expression was slightly decreased. In conclusion, the reciprocal expression of CYP17 and the transcriptional repressors COUP-TF and DAX-1 indicates that these orphan receptors have a pathophysiologic role in the excessive hormone production in cortisol- and deoxycorticosterone-producing adrenocortical tumors.

Adrenal Cortex Neoplasms↗
PubMed2000

[Efficacy and safety of cefozopran (CZOP) monotherapy and combination therapy with CZOP and amikacin (AMK) for infections accompanying hematological diseases].

We evaluated efficacy and safety of monotherapy with CZOP (1-2 g x 2/day) and combination therapy with CZOP (1-2 g x 2/day) and AMK (200 mg x 2/day) for infections in patients with hematological diseases. Efficacy was evaluated in 71 patients of monotherapy group and 70 patients of combination therapy group. Underlying diseases were mostly leukemia and lymphoma. Infections included sepsis, suspected sepsis, pneumonia and so on. Efficacy in CZOP monotherapy was excellent in 21 patients (31.3%), good in 23 patients (34.3%), fair in 5 patients (7.5%) and the efficacy rate was 65.7%. On the other hand, in combination therapy, each was 14 patients (21.2%), 23 patients (34.8%), 12 patients (18.2%) and the efficacy rate was 56.1%. Side effects such as eruption were noted in 2 patients. Abnormal laboratory findings were noted in 9 patients. All side effects as well as abnormal laboratory findings were minimal. It was concluded that CZOP monotherapy was effective in the treatment of various infections accompanying hematological diseases.

Adolescent↗
PubMed2000

[Two aged patients with chronic renal failure and chronic disseminated intravascular coagulation secondary to aortic aneurysms: effect of continuous subcutaneous heparin infusion therapy].

We describe here two cases of chronic disseminated intravascular coagulation(DIC) secondary to aortic aneurysms. The patients were 78- and 84-year-old males, who visited our hospital to receive hemodialysis therapy for chronic renal failure probably due to nephrosclerosis. They had mild bleeding tendency and thrombocytopenia(< 10 x 10(4)/microliter). Coagulation test revealed the findings of chronic DIC in both patients, and computed tomography showed abdominal and thoracoabdominal aortic aneurysms with mural thrombi, respectively. In one patient, subcutaneous hemorrhage after vascular access surgery had continued for a month. However, the hemorrhage and swelling of the limb disappeared after continuous subcutaneous heparin infusion(CSHI) therapy in a daily dose of 10,000-14,000 unit. These findings suggest that chronic DIC secondary to aortic aneurysm should be considered when bleeding tendency and thrombocytopenia are observed in aged patients, and that CSHI is the choice of therapy for the bleeding tendency of chronic DIC.

Aged↗
PubMed1999

Clinicopathological characteristics of interstitial foam cells in membranous nephropathy.

BACKGROUND: Interstitial foam cells are occasionally observed in various renal diseases, and they have been reported to belong to the monocyte/macrophage (M phi) lineage and to be associated with heavy proteinuria and hyperlipidemia. We investigated the characteristics of interstitial foam cells and their association with proteinuria and hyperlipidemia in idiopathic membranous nephropathy (MN). METHODS: Patients with MN (N = 320) were divided into two groups: group I consisted of 51 patients with interstitial foam cells, and group II consisted of the other 269 without foam cells. We compared clinical parameters and the findings of an immunohistochemical study using monoclonal antibodies to various types of leukocytes and adhesion molecules. RESULTS: The age at renal biopsy, the degree of proteinuria, serum levels of lipids, and other clinical parameters except for sex ratio were not different between the two groups. The ratio of nephrotic patients was compatible between groups I (56.9%) and II (52.8%). All interstitial foam cells were positive for CD68 and 25F9, which are markers for M phi and mature M phi, respectively, but were negative for CD3 or cytokeratin. Interstitial infiltrating cells were positive for CD68 and CD3 but were negative for 25F9. Furthermore, most of interstitial foam cells were positive for both leukocyte function associated antigen-1 (LFA-1) and intercellular adhesion molecule-1 (ICAM-1), but not for ICAM-3 (the third ligand for LFA-1). By contrast, most of infiltrating nonfoamy M phi s were positive for ICAM-3 and LFA-1, however, ICAM-1 was observed on only some of them. CONCLUSION: These results suggest that interstitial foam cells in MN may not depend on proteinuria nor hyperlipidemia directly. The accumulation of foam cells, which have characteristics of mature M phi, may be related to ICAM-1 as a ligand of LFA-1, whereas infiltration of nonfoamy M phi s has a close relationship with ICAM-3. Thus, the formation of interstitial foam cells may be related to the phenotypical transformation of M phi s.

Adult↗
PubMed1998

Successful treatment with steroid pulse therapy in a case of immunotactoid glomerulopathy with hypocomplementemia.

We report a case of immunotactoid glomerulopathy with severe hypocomplementemia. The patient was a 47-year-old woman who presented with pitting edema, proteinuria, and hypertension. Serological testings were negative or within normal limits except for hypocomplementemia. There were no findings of hematopoietic diseases, cryoglobulinemia, and systemic lupus erythematosus. The renal biopsy specimen showed membranoproliferative glomerulonephritis with numerous periodic acid-Schiff (PAS)-positive deposits. Under electron microscopy, however, microtubular structure was shown in the mesangial matrix and the subendothelial and subepithelial spaces of the peripheral capillary loops. These histological features were compatible with those of immunotactoid glomerulopathy. Although conventional oral steroid therapy failed to have an effect on proteinuria and hypocomplementemia over 3 months, steroid pulse therapy brought dramatic relief: complete remission of proteinuria and normalization of hypocomplementemia. These findings suggest that intensive immunosuppressive therapy may cure a kind of immunotactoid glomerulopathy with hypocomplementemia.

Biopsy↗
PubMed1998

COUP-TFI expression in human adrenocortical adenomas: possible role in steroidogenesis.

Chicken ovalbumin upstream promoter-transcription factor I (COUP-TFI) is an orphan nuclear receptor essential for neurogenesis, organogenesis, and cell fate determination. CYP17 gene transcription has recently been shown to be activated by SF-1 (steroidogenic factor-1) binding to a cyclic AMP-responsive sequence within the promoter region of the gene, and inhibited by COUP-TF binding to the sequence. Thus, COUP-TF and SF-1 act as a transcriptional repressor and activator, respectively, of CYP17 gene expression. Transcriptional repression by COUP-TFI is mediated by corepressors, N-CoR (nuclear receptor-corepressor) and SMRT (silencing mediator for retinoid and thyroid hormone-receptor), whereas transcriptional activation by SF-1 is mediated by coactivator SRC-1 (steroid receptor coactivator-1). We therefore examined the expression of COUP-TFI, SF-1, SRC-1, N-CoR, and SMRT in a variety of adrenocortical adenomas and compared the results with CYP17 mRNA levels. We found significantly high COUP-TFI mRNA expression in nonfunctional adenomas (n=8: 220+/-16%; normal 96+/-4%), a deoxycorticosterone-producing adenoma (n=1: 200%), and a pre-clinical Cushing's adenoma (n=1: 280%), intermediate COUP-TFI expression in cortisol-producing adenomas (n=8: 63+/-5%), and low COUP-TFI expression in aldosterone-producing adenomas (n=8: 49+/-4%). In contrast to COUP-TFI, SF-1 mRNA expression did not vary significantly among adrenals. We did not detect the expected negative correlation between COUP-TFI and CYP17 mRNA levels in adrenocortical adenomas. High COUP-TFI expression was associatedwith a nonfunctioning phenotype. Interestingly, the pattern of COUP-TFI expression was similar to the profile of N-CoR expression, but not of SMRT expression. These results indicate that COUP-TFI and N-CoR may play a role in steroidogenesis by human adrenocortical adenomas.

Adenoma↗
PubMed1998

[A case of hepatitis C virus associated membranous glomerulonephritis ameliorated by corticosteroid therapy].

We report a 50-year-old male patient with hepatitis C virus (HCV)-associated membranous glomerulonephritis (MN), for which he had been treated with corticosteroid therapy for one and a half years. This patient received blood infusion at 38 years of age. He visited our hospital because of liver dysfunction at 42 years. One year later, proteinuria and microhematuria were pointed out (43 years). Renal biopsy revealed MN with focal fibrocellular crescents. HBsAg, cryoglobulin, rheumatoid factor were all negative. Prednisolone was administered at the dose of 30 mg/day for 4 weeks and tapered subsequently. The steroid treatment was effective (urinary protein excretion: 4.2-->0.3 g/day, serum albumin: 2.4-->4.0 g/dl, 3 months later), and transaminase slightly elevated (GPT 50-->60-80 IU/l). One and a half years later he proved to be positive for HCV antibody, and corticosteroid administration was terminated. Subsequently proteinuria increased, and reached 3.0 g/day 6 years later. However, serological markers and ultrasonographic study for chronic hepatitis revealed mild changes of the liver. These findings suggest that corticosteroid therapy is not contraindicated against HCV-associated MN, and may possibly be used as the treatment for this condition.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1996

Effect of a nonpeptide vasopressin V1 antagonist (OPC-21268) on experimental accelerated focal glomerulosclerosis.

The effects of the nonpeptide orally effective vasopressin V1 receptor antagonist OPC-21268 were studied in progressive focal glomerulosclerosis (FGS) which developed in spontaneously hypercholesterolemic (SHC) rats with manifestations of hypercholesterolemia and proteinuria. Unilateral nephrectomy was performed at 7 weeks of age to accelerate spontaneous FGS. After nephrectomy, OPC-administered rats were fed chow containing 1% OPC-21268 for 9 weeks. Treatment with vasopressin V1 antagonist significantly reduced the rate of increase in the levels of triglyceride, systolic blood pressure, serum creatinine and BUN, and prevented a significant deterioration in creatinine clearance. Rats were sacrificed at 16 weeks of age. Histologically, the index of glomerular sclerosis in the OPC group showed a significant decrease compared to that in the control group (2.2 +/- 0.1 vs. 2.6 +/- 0.1, p < 0.01). Relative interstitial volume and glomerular volume in the OPC group showed a tendency to decrease compared to those in the control group. These results indicate that vasopressin plays an important role through V1 receptors in the development of glomerulosclerosis, and vasopressin V1 antagonist may prevent the progression of renal injury in glomerulosclerosis.

Animals↗
PubMed1996

[Clinicopathological study of interstitial foam cells in idiopathic membranous nephropathy. Consideration of the appearance of interstitial foam cells in renal tissue].

We conducted an immunohistological investigation on the pathogenesis of interstitial foam cell formation in patients with idiopathic membranous nephropathy (MN). The patients were divided into two groups: Group I consisted of 23 MN patients with interstitial foam cells; Group II consisted of the other 159 patients without foam cells. Age at renal biopsy, duration of proteinuria, blood pressure and other clinical parameters were not significantly different between the two groups. The proportion of nephrotic patients in Group I was 52.2% (12/23), and was not significantly different from that in Group II (48.4%, 77/159). Renal biopsy specimens were examined by immunoperoxidase studies using monoclonal antibodies. The interstitial foam cells were positive for EBM11 (CD68) and 25F9, which are markers of macrophage (M phi) and mature M phi, respectively, but did not express markers of T cells. In interstitial infiltrating cells, both M phi and T cells were observed, but mature M phi were seldom seen. Furthermore, LFA-1 and ICAM-1, but not ICAM-3 (the third ligand for LFA-1) were observed in the interstitial foam cells. LFA-1 and ICAM-3 were observed mainly in interstitial infiltrating cells, but ICAM-1 was observed to a much lesser extent in these cells. These results suggest that interstitial foam cells in MN may be independent of severe hyperlipidemia and proteinuria, and that there may be different mechanisms underlying the accumulation of interstitial foam cells and infiltrating m phi s. Further investigations are required to clarify the pathogenesis of interstitial foam cells in renal tissue.

Female↗
PubMed1994

[A case of IgA nephropathy with numerous interstitial foam cells--analysis of infiltrating mononuclear leucocytes in renal tissue].

A 27-year-old female was admitted to our hospital in order to examine proteinuria and microscopic hematuria. Light microscopic findings of her kidney showed proliferation of mesangial cells and numerous interstitial foam cells. Immunofluorescent and electron microscopic findings revealed IgA nephropathy. Immunoperoxidase studies using monoclonal antibodies disclosed that interstitial foam cells were positive for antibodies of the monocyte/macrophage lineage and also expressed adhesion molecules (CD11a, b, c, LFA-1) and MHC-class II antigens. Hereditary nephritis as Alport syndrome was negated by her familial history and electron microscopic study. We considered that it was a rare and interesting case with numerous interstitial foam cells, because the patient did not have hyperlipidemia as in nephrotic syndrome.

Adult↗