76
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Suzuki S, Hinokio Y, Komatu K, Ohtomo M, Onoda M, Hirai S, Hirai M, Hirai A, Chiba M, Kasuga S, Akai H, Toyota T. Oxidative damage to mitochondrial DNA and its relationship to diabetic complications. Diabetes Res Clin Pract 1999; 45:161-8. [PMID: 10588369 DOI: 10.1016/s0168-8227(99)00046-7] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Increased oxidative stress induced by hyperglycemia may contribute to the pathogenesis of diabetic complications. Oxidative stress is known to increase the conversion of deoxyguanosine (dG) to 8-hydroxydeoxyguanosine (8-OHdG) in DNA, which is linked to increased mitochondrial DNA (mtDNA) deletions. We investigated mtDNA deletions and 8-OHdG in the muscle DNA of non-insulin-dependent diabetes mellitus (NIDDM) patients. mtDNA deletion of 4977 bp (delta mtDNA4977) and the content of 8-OHdG in the muscle DNA of the NIDDM patients were much higher than those of the control subjects. There was a significant correlation between delta mtDNA4977 and the 8-OHdG content (P < 0.0001). Both delta mtDNA4977 and the 8-OHdG content were also correlated with the duration of diabetes. Delta mtDNA4977 and the 8-OHdG content in muscle DNA increased in proportion to the severity of diabetic nephropathy and retinopathy. This is the first report that an increase in delta mtDNA4977 and 8-OHdG is proportional to the severity of diabetic complications. Oxidative mtDNA damage is speculated to contribute to the pathogenesis of diabetic complications though a defect in mitochondrial oxidative phosphorylation or other mechanisms. 8-OHdG and delta mtDNA4977 are useful markers to evaluate oxidative mtDNA damage in the diabetic patients.
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77
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Kubo N, Harada K, Hirai A, Kadowaki K. A single nuclear transcript encoding mitochondrial RPS14 and SDHB of rice is processed by alternative splicing: common use of the same mitochondrial targeting signal for different proteins. Proc Natl Acad Sci U S A 1999; 96:9207-11. [PMID: 10430921 PMCID: PMC17758 DOI: 10.1073/pnas.96.16.9207] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The rice mitochondrial genome has a sequence homologous to the gene for ribosomal protein S14 (rps14), but the coding sequence is interrupted by internal stop codons. A functional rps14 gene was isolated from the rice nuclear genome, suggesting a gene-transfer event from the mitochondrion to the nucleus. The nuclear rps14 gene encodes a long N-terminal extension showing significant similarity to a part of mitochondrial succinate dehydrogenase subunit B (SDHB) protein from human and a malarial parasite (Plasmodium falciparum). Isolation of a functional rice sdhB cDNA and subsequent sequence comparison to the nuclear rps14 indicate that the 5' portions of the two cDNAs are identical. The sdhB genomic sequence shows that the SDHB-coding region is divided into two exons. Surprisingly, the RPS14-coding region is located between the two exons. DNA gel blot analysis indicates that both sdhB and rps14 are present at a single locus in the rice nucleus. These findings strongly suggest that the two gene transcripts result from a single mRNA precursor by alternative splicing. Protein blot analysis shows that the size of the mature RPS14 is 16.5 kDa, suggesting removal of the N-terminal 22.6-kDa peptide region. Considering that the rice mitochondrial genome lacks the sdhB gene but contains the rps14-related sequence, transfer of the sdhB gene seems to have occurred before the transfer of the rps14 gene. The migration of the mitochondrial rps14 sequence into the already existing sdhB gene could bestow the capacity for nuclear expression and mitochondrial targeting.
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78
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Wakamoto H, Hirai A, Manabe K, Hayashi M. Idiopathic small-fiber sensory neuropathy in childhood: A diagnosis based on objective findings on punch skin biopsy specimens. J Pediatr 1999; 135:257-60. [PMID: 10431124 DOI: 10.1016/s0022-3476(99)70032-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Idiopathic small-fiber sensory neuropathy (SFSN) has not previously been reported in children. Although affected patients complain of neuropathic pain, this condition is often difficult to diagnose because of the few objective physical signs and normal nerve conduction studies. We report a girl with idiopathic SFSN in whom the results of a sural nerve biopsy were normal, but punch skin biopsy revealed reduced intraepidermal nerve fiber density and established the diagnosis. Idiopathic SFSN should be considered in the differential diagnosis of children who have burning limb pain with no routine electrophysiologic or pathologic abnormalities.
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79
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Hinokio Y, Suzuki S, Hirai M, Chiba M, Hirai A, Toyota T. Oxidative DNA damage in diabetes mellitus: its association with diabetic complications. Diabetologia 1999; 42:995-8. [PMID: 10491760 DOI: 10.1007/s001250051258] [Citation(s) in RCA: 156] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
AIMS/HYPOTHESIS Augmented oxidative stress induced by hyperglycaemia possibly contributes to the pathogenesis of diabetic complications. Oxidative stress is known to increase the conversion of deoxyguanosine to 8-oxo, 2'-deoxyguanosine in DNA. To investigate the possible contribution of oxidative DNA damage to the pathogenesis of diabetic complications, we measured the content of 8-oxo, 2'-deoxyguanosine in the urine and the blood mononuclear cells of Type II (non-insulin-dependent) diabetic patients. METHODS We studied 53 Type II diabetic patients and 39 age-matched healthy control subjects. We assayed 8-oxo, 2'-deoxyguanosine by HPLC-electrochemical detection method. RESULTS The content of 8-oxo, 2'-deoxyguanosine in the urine and the mononuclear cells of the Type II diabetic patients was much higher than that of the control subjects. Urinary 8-oxo, 2'-deoxyguanosine excretion and the 8-oxo, 2'-deoxyguanosine content in the mononuclear cells from the diabetic patients with complications were higher than those from the diabetic patients without complications. Urinary excretion of 8-oxo, 2'-deoxyguanosine was significantly correlated with the 8-oxo, 2'-deoxyguanosine content in the mononuclear cells. The 8-oxo, 2'-deoxyguanosine content in the urine and mononuclear cells was correlated with the haemoglobin A1c value. CONCLUSIONS/INTERPRETATION This is the first report of a direct association between oxidative DNA damage and the complications of diabetes. The augmented oxidative DNA damage in diabetes is speculated to contribute to the pathogenesis of diabetic complications.
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80
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Nishimura M, Tanaka T, Yasuda T, Kurakata S, Kitagawa M, Yamada K, Saito Y, Hirai A. Effect of pravastatin on type IV collagen secretion and mesangial cell proliferation. KIDNEY INTERNATIONAL. SUPPLEMENT 1999; 71:S97-100. [PMID: 10412748 DOI: 10.1046/j.1523-1755.1999.07124.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The mevalonate pathway is important for the biosynthesis of isoprenoids such as geranylgeranylpyrophosphate (GGPP) and farnesylpyrophosphate (FPP) as well as cholesterol. It has been reported that treatment with 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor ameliorates glomerular injury in several experimental models of progressive glomerular disease. The present investigation was performed to elucidate the role of mevalonate metabolites in mesangial cell proliferation and extracellular matrix accumulation. METHOD Cycling or quiescent human mesangial cells were incubated in RPMI1640 containing 10% heat-inactivated fetal calf serum (FCS) in the absence or presence of pravastatin, an inhibitor of HMG-CoA reductase, and mevalonate metabolites. Type IV collagen secretion and mRNA expression, [3H]-thymidine incorporation was measured. Cell cycle phases were monitored by flow cytometry. RESULTS Pravastatin inhibited FCS-stimulated type IV collagen secretion (IC50 = 210 microM) and mRNA expression. Pravastatin also inhibited FCS-stimulated [3H]-thymidine incorporation (IC50 = 430 microM). Analysis with flow cytometry revealed that pravastatin inhibited G1 to S phase transition of FCS-stimulated mesangial cells. Mevalonate reversed these inhibitory effects of pravastatin completely. Among two major metabolities of mevalonate, GGPP and FPP, only GGPP reversed pravastatin-induced inhibition of type IV collagen secretion, DNA synthesis and G1 to S phase progression. CONCLUSION The present results suggest that GGPP plays a critical role in the type IV collagen secretion and G1 to S phase transition in FCS-stimulated human mesangial cells.
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81
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Hamanaka S, Ohtsu K, Kadowaki K, Nakazono M, Hirai A. Identification of cDNA encoding cytochrome c oxidase subunit 5c (COX5c) from rice: comparison of its expression with nuclear-encoded and mitochondrial-encoded COX genes. Genes Genet Syst 1999; 74:71-5. [PMID: 10586516 DOI: 10.1266/ggs.74.71] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Little is presently known about the nuclear-encoded genes for cytochrome c oxidase (COX) in higher plants. In rice, only the nuclear-encoded COX5b gene has been reported. To understand the relationship between the expression of nuclear-encoded and mitochondrial-encoded COX genes in rice, we first characterized a cDNA encoding one of the other nuclear COX genes, COX5c, which encodes 63 amino acids. The deduced amino acid sequence of COX5c from rice was highly homologous to that from sweet potato. Genomic Southern hybridization indicated that the rice COX5c subunit is encoded by a single copy of the COX5c gene. Furthermore, we compared the expression patterns of the nuclear-encoded COX5c and COX5b genes with the expression pattern of the mitochondrial-encoded COX1 gene among several organs by Northern blot analysis. The results suggested that regulatory systems of expression between the nuclear-encoded and the mitochondrial-encoded COX genes are different among different organs in rice.
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82
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Shirane M, Harumiya Y, Ishida N, Hirai A, Miyamoto C, Hatakeyama S, Nakayama K, Kitagawa M. Down-regulation of p27(Kip1) by two mechanisms, ubiquitin-mediated degradation and proteolytic processing. J Biol Chem 1999; 274:13886-93. [PMID: 10318797 DOI: 10.1074/jbc.274.20.13886] [Citation(s) in RCA: 177] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The intracellular level of p27(Kip1), a cyclin-dependent kinase (CDK) inhibitory protein, is rapidly reduced at the G1/S transition phase when the cell cycle pause ceases. In this study, we demonstrated that two posttranslational mechanisms were involved in p27(Kip1) breakdown: degradation via the ubiquitin (Ub)-proteasome pathway and proteolytic processing that rapidly eliminates the cyclin-binding domain. We confirmed that p27(Kip1) was ubiquitinated in vitro as well as in vivo. The p27(Kip1) -ubiquitination activity was higher at the G1/S boundary than during the G0/G1 phase, and p27(Kip1) ubiquitination was reduced significantly when the lysine residues at positions 134, 153, and 165 were replaced by arginine, suggesting that these lysine residues are the targets for Ub conjugation. In parallel with its Ub-dependent degradation, p27(Kip1) was processed rapidly at its N terminus, reducing its molecular mass from 27 to 22 kDa, by a ubiquitination-independent but adenosine triphosphate (ATP)-dependent mechanism with higher activity during the S than the G0/G1 phase. This 22-kDa intermediate had no cyclin-binding domain at its N terminus and virtually no CDK2 kinase inhibitory activity. These results suggest that p27(Kip1) is eliminated by two independent mechanisms, ubiquitin-mediated degradation and ubiquitin-independent processing, during progression from the G1 to S phase.
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83
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Arimura S, Takusagawa S, Hatano S, Nakazono M, Hirai A, Tsutsumi N. A novel plant nuclear gene encoding chloroplast ribosomal protein S9 has a transit peptide related to that of rice chloroplast ribosomal protein L12. FEBS Lett 1999; 450:231-4. [PMID: 10359080 DOI: 10.1016/s0014-5793(99)00491-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have cloned a novel nuclear gene for a ribosomal protein of rice and Arabidopsis that is like the bacterial ribosomal protein S9. To determine the subcellular localization of the gene product, we fused the N-terminal region and green fluorescent protein and expressed it transiently in rice seedlings. Localized fluorescence was detectable only in chloroplasts, indicating that this nuclear gene encodes chloroplast ribosomal protein S9. The N-terminal region of rice ribosomal protein S9 was found to have a high sequence similarity to the transit peptide region of the rice chloroplast ribosomal protein L12, suggesting that these transit peptides have a common lineage.
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84
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Nakamura S, Tatuno I, Noguchi Y, Kitagawa M, Kohn LD, Saito Y, Hirai A. 73-kDa heat shock cognate protein interacts directly with P27Kip1, a cyclin-dependent kinase inhibitor, during G1/S transition. Biochem Biophys Res Commun 1999; 257:340-3. [PMID: 10198213 DOI: 10.1006/bbrc.1999.0442] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although heat shock proteins (HSPs) were discovered as inducible proteins by the physical stress to protect cells, recent evidence has suggested that HSPs are likely involved in cell cycle control under normal conditions without stress. In the present study, we demonstrated that 73hsc (heat shock cognate protein), which belongs to the HSP70 family of molecular chaperones, interacts with P27Kip1, an inhibitor of cyclin-dependent kinase, during G1/S transition. 73hsc was detected in the immunoprecipitates with anti-P27Kip1 antibody and, vice versa, P27Kip1 was present in the immunoprecipitates with anti-73hsc antibody by Western blotting using growth-stimulated rat thyroid FRTL-5 cells. This complex formation of 73hsc and P27Kip1 was cell cycle dependent and its maximum formation was observed at G1/S transition where the level of P27Kip1 dramatically decreased. ATP dissociated this complex formation in a dose-dependent manner. These data indicated that 73hsc might be involved in the cell cycle progression through the regulation of cell cycle regulators such as P27Kip1.
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85
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Abstract
A 58-year-old woman was hospitalized because of progressive respiratory distress. She had a history of myasthenia gravis and invasive thymoma. After thymectomy, she had been administered oral prednisolone and intrathoracic anti-cancer drugs postoperatively. Her chest radiograph revealed bilateral pleural effusions. Legionella micdadei (L. micdadei) was isolated from the pleural effusions, and she was diagnosed as pleuritis caused by L. micdadei. She died despite intensive therapy with mechanical ventilation, drainage tube in the chest and intravenous erythromycin. Although only two cases of Legionellosis caused by L. micdadei have been reported in Japan, clinicians should be aware of L. micdadei as one of the candidates for infection in immunosuppressed hosts.
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86
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Terano T, Shiina T, Noguchi Y, Tanaka T, Tatsuno I, Saito Y, Yasuda T, Kitagawa M, Hirai A. Geranylgeranylpyrophosphate plays a key role for the G1 to S transition in vascular smooth muscle cells. J Atheroscler Thromb 1999; 5:1-6. [PMID: 10077451 DOI: 10.5551/jat1994.5.1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Pravastatin, a HMG-CoA reductase inhibitor was found to inhibit DNA synthesis of vascular smooth muscle cells (VSMC) in a dose-dependent manner. Flow cytometric analysis demonstrated that pravastatin induced G1 arrest. Mevalonate restored the inhibitory effect of pravastatin on DNA synthesis and on cell cycle progression, suggesting the importance of mevalonate itself and/or its metabolites in VSMC proliferation. The major intermediate metabolites of mevalonate, geranylgeranyl-pyrophosphate (GGPP), farnesyl pyrophosphate (FPP) and IPP (isopentenyl pyrophosphate) were prepared in the form of liposomes, and the effects of GGPP, FPP and IPP on pravastatin induced inhibition of VSMC proliferation and G1 arrest were examined. Only GGPP restored the pravastatin-induced inhibition of DNA synthesis and G1 arrest. Pravastatin inhibited translocation of Rho small GTPase from cytosol to membrane. By the addition of GGPP, Rho small GTPase are geranylgeranylated and translocated to membranes during G1/S transition. These data suggest that GGPP, rather than FPP or IPP, is an essential metabolite among mevalonic acid metabolites for VSMC proliferation and the G1/S transition.
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87
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Nishimura M, Tanaka T, Yasuda T, Kurakata S, Kitagawa M, Yamada K, Saito Y, Hirai A. Collagen secretion and growth of mesangial cells require geranylgeranylpyrophosphate. Kidney Int 1999; 55:520-8. [PMID: 9987076 DOI: 10.1046/j.1523-1755.1999.00292.x] [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: 11/20/2022]
Abstract
BACKGROUND The mevalonate pathway is important for the biosynthesis of isoprenoids such as geranylgeranylpyrophosphate (GGPP) and farnesylpyrophosphate, as well as cholesterol. It has been reported that treatment with 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor ameliorates glomerular injury in several experimental models of progressive glomerular disease. However, the effect of HMG-CoA reductase inhibitor on mesangial cell function has not been fully understood. This investigation was performed to elucidate the role of a mevalonate metabolite(s) in mesangial cell proliferation and extracellular matrix accumulation. METHODS Cycling or quiescent human mesangial cells were incubated in RPMI 1640 containing 10% heat-inactivated fetal calf serum (FCS) in the absence or presence of pravastatin, an inhibitor of HMG-CoA reductase, and mevalonate metabolites. Type IV collagen secretion, mRNA expression, and [3H]thymidine incorporation were measured. Cell cycle phases were monitored by flow cytometry. RESULTS Pravastatin inhibited FCS-stimulated type IV collagen secretion (IC50 = 210 microM) and mRNA expression. Pravastatin also inhibited FCS-stimulated [3H]thymidine incorporation (IC50 = 430 microM). Analysis with flow cytometry revealed that pravastatin inhibited the G1 to S phase transition of FCS-stimulated mesangial cells. Mevalonate reversed these inhibitory effects of pravastatin completely. Among two major metabolites of mevalonate, GGPP and farnesylpyrophosphate, only GGPP reversed pravastatin-induced inhibition of type IV collagen secretion, DNA synthesis, and the G1 to S phase progression. CONCLUSIONS These results suggest that GGPP plays critical roles for the type IV collagen secretion and G1 to S phase transition in FCS-stimulated human mesangial cells.
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88
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Terano T, Tanaka T, Tamura Y, Kitagawa M, Higashi H, Saito Y, Hirai A. Eicosapentaenoic acid and docosahexaenoic acid inhibit vascular smooth muscle cell proliferation by inhibiting phosphorylation of Cdk2-cyclinE complex. Biochem Biophys Res Commun 1999; 254:502-6. [PMID: 9918868 DOI: 10.1006/bbrc.1998.9976] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the form of triacylglycerol (TG) were dose dependently incorporated into phospholipid fraction of vascular smooth muscle cells (VSMC) and suppressed the proliferation of VSMC. Flow cytometric analysis demonstrated both EPA and DHA inhibited G1/S progression. EPA and DHA inhibited the phosphorylation of Cdk2 protein and Cdk2 kinase activity without altering the amount of cyclin E and p27(kip1) proteins and cyclin dependent kinase activating kinase activity by growth stimulation. This mechanisms remained to be clarified but this is the first report of a novel mechanisms of inhibition of DNA synthesis by EPA and DHA.
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MESH Headings
- Animals
- Aorta, Thoracic/cytology
- Aorta, Thoracic/drug effects
- Aorta, Thoracic/metabolism
- CDC2-CDC28 Kinases
- Cell Cycle/drug effects
- Cell Cycle/physiology
- Cell Division/drug effects
- Cells, Cultured
- Cyclin E/metabolism
- Cyclin-Dependent Kinase 2
- Cyclin-Dependent Kinases/metabolism
- Docosahexaenoic Acids/pharmacology
- Eicosapentaenoic Acid/pharmacology
- Emulsions
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Phosphorylation
- Protein Serine-Threonine Kinases/metabolism
- Rats
- Rats, Inbred WKY
- Thymidine/metabolism
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Saito T, Sugiura C, Hirai A, Notani K, Totsuka Y, Shindoh M, Kohgo T, Fukuda H. High malignant transformation rate of widespread multiple oral leukoplakias. Oral Dis 1999; 5:15-9. [PMID: 10218036 DOI: 10.1111/j.1601-0825.1999.tb00058.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE This study was undertaken in order to investigate clinicopathologic characteristics and malignant potential of widespread multiple oral leukoplakias. PATIENTS AND METHODS The present study includes 12 patients with widespread multiple leukoplakias (widespread patients) and 99 with localized lesions (localized patients), and all patients were followed for more than 6 months with the mean follow-up period of 4 years. RESULTS Gingiva and tongue were the major affected sites of leukoplakias in the localized patients, whereas gingiva and buccal mucosa were predominantly affected in the widespread patients. The rate of developing carcinoma was significantly (P < 0.02) higher in the widespread patients (3/12) than in the localized patients (5/99), although there was no significant difference in the rate of dysplastic lesions between these groups. CONCLUSION These results indicate that the widespread leukoplakias have a higher potential for the development of carcinoma than do the localized lesions.
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90
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Uchida D, Tatsuno I, Tanaka T, Hirai A, Saito Y, Moro O, Tajima M. Maxadilan is a specific agonist and its deleted peptide (M65) is a specific antagonist for PACAP type 1 receptor. Ann N Y Acad Sci 1998; 865:253-8. [PMID: 9928019 DOI: 10.1111/j.1749-6632.1998.tb11185.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Maxadilan is a potent vasodilator peptide isolated from salivary glands extracts of the hematophagous sand fly. Recently, it was demonstrated that maxadilan binds to PACAP receptor type 1 in mammals, although maxadilan has no significant amino acid sequence homology with PACAP. In the present study, we demonstrated that maxadilan is a specific agonist of PACAP type 1 receptor (PACAP/VIP receptor 1; PVR1) as determined by the binding assay of [125I]PACAP27 and cAMP accumulation using CHO cells stably expressing PVR1, VIP1 receptor (PVR2), and VIP2 receptor (PVR3), and that the deleted peptide (#25-41) of maxadilan (termed as M65) is a specific antagonist of PVR1. In addition, maxadilan shares the binding sites for PACAP and stimulates cAMP in cultured rat cortical neurons. VIP stimulates cAMP accumulation probably through the binding to PVR1 since M65 blocks the VIP-induced cAMP accumulation in cultured rat cortical neurons.
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MESH Headings
- Amino Acid Sequence
- Animals
- CHO Cells
- Cells, Cultured
- Cerebral Cortex/cytology
- Cerebral Cortex/physiology
- Cricetinae
- Cyclic AMP/metabolism
- Fetus
- Insect Proteins/chemistry
- Insect Proteins/pharmacology
- Molecular Sequence Data
- Neurons/cytology
- Neurons/drug effects
- Neurons/physiology
- Neuropeptides/chemistry
- Peptide Fragments/chemistry
- Peptide Fragments/pharmacology
- Pituitary Adenylate Cyclase-Activating Polypeptide
- Protein Structure, Secondary
- Rats
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I
- Receptors, Pituitary Hormone/agonists
- Receptors, Pituitary Hormone/antagonists & inhibitors
- Receptors, Pituitary Hormone/genetics
- Receptors, Pituitary Hormone/physiology
- Receptors, Vasoactive Intestinal Peptide/physiology
- Receptors, Vasoactive Intestinal Peptide, Type II
- Receptors, Vasoactive Intestinal Polypeptide, Type I
- Recombinant Proteins/chemistry
- Recombinant Proteins/pharmacology
- Reverse Transcriptase Polymerase Chain Reaction
- Salivary Proteins and Peptides/chemistry
- Salivary Proteins and Peptides/pharmacology
- Sequence Alignment
- Sequence Deletion
- Sequence Homology, Amino Acid
- Vasoactive Intestinal Peptide/chemistry
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91
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Tanaka T, Tatsuno I, Noguchi Y, Uchida D, Oeda T, Narumiya S, Yasuda T, Higashi H, Kitagawa M, Nakayama K, Saito Y, Hirai A. Activation of cyclin-dependent kinase 2 (Cdk2) in growth-stimulated rat astrocytes. Geranylgeranylated Rho small GTPase(s) are essential for the induction of cyclin E gene expression. J Biol Chem 1998; 273:26772-8. [PMID: 9756921 DOI: 10.1074/jbc.273.41.26772] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The role of the mevalonate cascade in the control of cell cycle progression in astrocytes has been investigated. Serum stimulation of rat astrocytes in primary culture induces the expression of cyclin E followed by the activation of cyclin-dependent kinase 2 (Cdk2) during G1/S transition. The expression of p27, cyclin D1, and the activities of Cdk4 and Cdk-activating kinase (CAK), composed of Cdk7 and cyclin H, were not affected. Serum did, however, stimulate the expression of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase mRNA at mid-G1 phase. Moreover, an inhibitor of HMG-CoA reductase, pravastatin, reduced cyclin E expression and Cdk2 activation and caused G1 arrest in the astrocytes. In contrast, mevalonate and its metabolite, geranylgeranylpyrophosphate (GGPP) but not farnesylpyrophosphate (FPP), reversed the inhibitory effects of pravastatin on cyclin E expression and Cdk2 activation and allowed G1/S transition. Rho small GTPase(s) were geranylgeranylated and translocated to membranes in the presence of GGPP during G1/S transition. The effect of GGPP on cyclin E expression was abolished by botulinum C3 exoenzyme, which specifically inactivates Rho. These data indicate that geranylgeranylated Rho small GTPase(s) are essential for the induction of cyclin E expression, Cdk2 activation, and G1/S transition in rat astrocytes.
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92
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Miyata S, Nakazono M, Hirai A. Transcription of plastid-derived tRNA genes in rice mitochondria. Curr Genet 1998; 34:216-20. [PMID: 9745025 DOI: 10.1007/s002940050389] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Previous investigations located nine of the genes for rice tRNAs on plastid (pt)-derived sequences in mitochondrial DNA. In the present study, we examined whether these genes were also transcribed in rice mitochondria. Northern-blot hybridization revealed that seven of these genes (trnC, trnF, trnH, trnM, trnN, trnS and trnW) are transcribed and are precisely processed to mature tRNAs. One of the other two genes (trnP) is transcribed but cannot be processed efficiently, while the other (trnR), which has 100% identity to the original plastid tRNAArg gene, is not transcribed in rice mitochondria. These results suggest that seven of the nine pt-derived tRNAs may be utilized for the biosynthesis of protein in plant mitochondria.
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MESH Headings
- DNA Probes/genetics
- DNA, Mitochondrial/genetics
- Evolution, Molecular
- Gene Expression Regulation, Plant/genetics
- Genes, Plant/genetics
- Mitochondria/genetics
- Oryza/genetics
- Plastids/genetics
- RNA/genetics
- RNA, Messenger/metabolism
- RNA, Mitochondrial
- RNA, Transfer/genetics
- RNA, Transfer, Arg/genetics
- Transcription, Genetic/genetics
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93
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Kawana H, Tamaru J, Tanaka T, Hirai A, Saito Y, Kitagawa M, Mikata A, Harigaya K, Kuriyama T. Role of p27Kip1 and cyclin-dependent kinase 2 in the proliferation of non-small cell lung cancer. THE AMERICAN JOURNAL OF PATHOLOGY 1998; 153:505-13. [PMID: 9708810 PMCID: PMC1852977 DOI: 10.1016/s0002-9440(10)65593-9] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/08/1998] [Indexed: 11/20/2022]
Abstract
The cell cycle is governed by a family of cyclin-dependent kinases (Cdks). Cdk2 forms a functional complex with cyclin E and plays a pivotal role in the regulation of G1/S transition. Cdk2 activity is negatively regulated by interactions with inhibitors. p27Kip1, one of the most potent inhibitors of Cdk2, was recently identified as a powerful negative prognostic marker in non-small cell lung cancer as well as in colorectal and breast cancer. In the present study, the expression of p27 and Ki-67 antigen in nonneoplastic and cancerous lung tissues was determined by immunohistochemistry. After establishing that the antibody-measured p27 labeling index was a good reflection of the level of p27 expression measured by Western blotting, we show that p27 labeling index is decreased in cancerous lung tissues, compared with nonneoplastic lung tissues, and exhibits a significant inverse relation to the proliferation marker Ki-67 antigen, detected with monoclonal antibody MIB-1. Consistent with these data, all cancerous lung tissues showed enhanced degradation activity of p27 compared with nonneoplastic lung tissues and, in addition, increased levels of the phosphorylated form of Cdk2, as determined with Western blot analysis. The H1 histone kinase activity associated with Cdk2 was also increased in non-small cell lung cancers. Statistical analysis showed that proliferative activity as measured by MIB-1 labeling index was highly correlated with Cdk2 activity (r = 0.767, P < 0.0015). These results suggest that p27 and Cdk2 may play an important role in the proliferation of non-small cell cancer.
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94
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Furuya R, Hirai A, Andoh T, Kudoh I, Okumura F. Successful perioperative management of a patient with Parkinson's disease by enteral levodopa administration under propofol anesthesia. Anesthesiology 1998; 89:261-3. [PMID: 9667318 DOI: 10.1097/00000542-199807000-00035] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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95
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Moroo I, Tatsuno I, Uchida D, Tanaka T, Saito J, Saito Y, Hirai A. Pituitary adenylate cyclase activating polypeptide (PACAP) stimulates mitogen-activated protein kinase (MAPK) in cultured rat astrocytes. Brain Res 1998; 795:191-6. [PMID: 9622627 DOI: 10.1016/s0006-8993(98)00291-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Astrocytes, a subtype of glial cells, have been demonstrated to have an abundant number of receptors for pituitary adenylate cyclase activating polypeptide (PACAP), a neuropeptide of the VIP/secretin family which stimulates cAMP accumulation 1000 times more potent than VIP in astrocytes. PACAP is reported to stimulate the proliferation of astrocytes at low concentrations at which it does not yet stimulate the cAMP accumulation. In the present study, we examined the effect of PACAP on the activation of mitogen-activated protein kinase (MAPK), one of the important intracellular signals for the proliferation, and compared it with that of epidermal growth factor (EGF). To investigate the activation of MAPK, we focused on ERK2, one of MAPK, in cultured rat astrocytes. The activation of ERK2 was determined by immunoblotting and measurement of the activity in terms of the phosphorylating activity of immunoprecipitates with MAPK antibody on myelin basic protein. One pM of PACAP38 temporarily activated ERK2 at 10 min. In contrast, EGF activated ERK2 from 10 min to 60 min continuously. As for the dose-response effect, PACAP stimulated ERK2 at as low a concentration as 10-14 M and peaked at 10-12 M. Thereafter, its activating effect gradually decreased at 10-10 M and returned to the basal level at 10-8 M, forming a bell-shaped dose-dependency. Neither an inhibitor of PKA (H89) nor inhibitors of PKC (staurosporine and calphostin C) had any effect on the ERK2 activation induced by 1 pM PACAP38. Dibutyryl cAMP suppressed ERK2 activity in a dose-dependent manner. These data clearly demonstrated that PACAP stimulates MAPK in both a PKA- and a PKC-independent manner in cultured rat astrocytes.
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96
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Hirai M, Suzuki S, Hinokio Y, Chiba M, Kasuga S, Hirai A, Toyota T. Group specific component protein genotype is associated with NIDDM in Japan. Diabetologia 1998; 41:742-3. [PMID: 9662062 DOI: 10.1007/s001250050980] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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97
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Kanazawa A, Tsutsumi N, Hirai A. Differential changes in copy numbers of rice mitochondrial plasmid-like DNAs and main mitochondrial genomic DNAs that depend on temperature. Curr Genet 1998; 33:437-44. [PMID: 9644207 DOI: 10.1007/s002940050357] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The mitochondria of rice contain four kinds of circular plasmid-like DNAs, namely, B1, B2, B3 and B4, in addition to the main mitochondrial genomic DNAs. In order to examine the genetic stability of mitochondrial plasmid-like DNAs, changes in the amounts of plasmid-like DNAs and main mitochondrial genomic DNAs were analyzed in calli that had been cultured at various temperatures. The observed effect of temperature on the levels of plasmid-like DNAs was larger than that on the main mitochondrial genomic DNAs. A significant reduction in the copy number of plasmid-like DNAs was detected in calli cultured at 35 degrees C, as compared to 20 degrees C, 25 degrees C and 30 degrees C. The effect of temperature on DNA synthesis in isolated mitochondria was also analyzed. Synthesis of the main mitochondrial genomic DNAs occurred at all the temperatures examined, whereas synthesis of plasmid-like DNAs occurred only over a limited range of temperatures. The results of both in vivo and in vitro analyses suggest that plasmid-like DNAs are less stably maintained than the main mitochondrial genomic DNAs, which is consistent with the notion that the transmission of mitochondrial plasmid-like DNAs from one generation to the next may be unstable under unusual conditions.
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98
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Hirai A, Kohno N, Nishihara T, Kaneda K, Nakae S, Kawamura T, Kanbara Y, Nakaya S, Ishikawa Y, Sashikata T. A case of intraductal papilloma of breast in advanced age. THE KOBE JOURNAL OF MEDICAL SCIENCES 1998; 44:127-33. [PMID: 10209933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Breast tumors have their various biological characteristics as to advanced age of patients. Intraductal papilloma is a benign tumor of the breast which is known to occur in the premenopausal young females. Tumors of the breast in the senile females are found mainly to be breast cancers. No any cases of intraductal papilloma over 80-years were reported in Japan to date. We have recognized mammary tumors in old aged patients to be cancers, but it is necessary to put it into mind there are a few intraductal papillomas even if advanced in age. In this report, we present the most senile case with intraductal papilloma in our institute.
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99
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Hirai A, Usami M, Haji S, Kasahara H, Kotani G, Iso A, Kitamura Y, Sen H, Yamamoto M, Saitoh Y. Changes of polymorphonuclear leukocyte (PMN) functions under dietary nucleic acid deficiency and effects of administration of nucleotide and nucleosides mixture solution in mice. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1998; 431:543-7. [PMID: 9598125 DOI: 10.1007/978-1-4615-5381-6_105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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100
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Usami M, Ogino M, Kasahara H, Haji S, Hirai A, Kotani G, Kitamura Y, Tagawa Y, Sen H, Iso A, Sakata K, Yamamoto M, Saitoh Y. A nucleotide and nucleosides mixture solution improves recovery of energy metabolism after hepatic ischemia in rats. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1998; 431:389-93. [PMID: 9598098 DOI: 10.1007/978-1-4615-5381-6_78] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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