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Nguyen LT, Uchida T, Tsukamoto Y, Kuroda A, Okimoto T, Kodama M, Murakami K, Fujioka T, Moriyama M. Helicobacter pylori dupA gene is not associated with clinical outcomes in the Japanese population. Clin Microbiol Infect 2009. [PMID: 19832706 DOI: 10.1111/j.1469-0691.2009.03081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The dupA gene of Helicobacter pylori was suggested to be a risk factor for duodenal ulcer but protective against gastric cancer. The present study aimed to re-examine the role of dupA in H. pylori-infected Japanese patients. We found that dupA status was not associated with any gastroduodenal disease, histological score of chronic gastritis or with the extent of interleukin-8 production from gastric cell lines. These results indicate that dupA is unlikely to be a virulence factor of H. pylori in the Japanese population.
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Yamashita H, Mori K, Kuroda A, Nakai T. Neutralizing antibody levels for protection against betanodavirus infection in sevenband grouper, Epinephelus septemfasciatus (Thunberg), immunized with an inactivated virus vaccine. JOURNAL OF FISH DISEASES 2009; 32:767-775. [PMID: 19490392 DOI: 10.1111/j.1365-2761.2009.01054.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Abstract An inactivated betanodavirus, red-spotted grouper nervous necrosis virus (RGNNV), is a vaccine candidate for viral nervous necrosis (VNN). The present study was conducted to examine inoculation doses of the vaccine and neutralizing antibody titre levels to protect fish against VNN. Young sevenband grouper, Epinephelus septemfasciatus, averaging 25.4 g, were immunized at 25 degrees C water temperature by a single intraperitoneal injection of formalin-inactivated RGNNV. Fish immunized at vaccine doses of 10(8.5), 10(8.0), 10(7.5), 10(7.0) and 10(6.5) TCID(50) per fish produced antibodies at mean titres of 1:907, 1:511, 1:259, 1:197 and 1:96, respectively, at 20 days post-immunization (p.i.). Neutralizing antibodies were not detected in any control fish (titre <1:80). When fish were challenged with RGNNV (10(5.0) and 10(4.0) TCID(50)/fish) at 20 days p.i., cumulative mortalities of the fish groups immunized with 10(8.5), 10(8.0), 10(7.5) and 10(7.0) TCID(50) per fish were significantly lower than those of the control group, and the relative percent survival values were higher than 60% in fish groups immunized with 10(7.5) TCID(50) per fish or higher doses. However, no significant differences were found in mortality between the group immunized with 10(6.5) TCID(50) per fish and the control group. From these results, it was deduced that the minimum effective inoculation dose of the vaccine is 10(7.0) TCID(50) per fish and the minimum mean neutralizing antibody titre giving significant protection is approximately 1:200. This antibody titre level is a possible measure of vaccine efficacy against VNN in sevenband grouper, instead of a virus challenge test.
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Todorov I, Nair I, Ferreri K, Rawson J, Kuroda A, Pascual M, Omori K, Valiente L, Orr C, Al-Abdullah I, Riggs A, Kandeel F, Mullen Y. Multipotent progenitor cells isolated from adult human pancreatic tissue. Transplant Proc 2006; 37:3420-1. [PMID: 16298614 DOI: 10.1016/j.transproceed.2005.09.088] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The supply of islet cells is a limiting factor for the widespread application of islet transplantation of type-1 diabetes. Islets constitute 1% to 2% of pancreatic tissue, leaving approximately 98% as discard after islet isolation and purification. In this report we present our data on the isolation of multipotent progenitor cells from discarded adult human pancreatic tissue. The collected cells from discarded nonislet fractions, after enzymatic digestion and gradient purification of islets, were dissociated for suspension culture in a serum-free medium. The cell clusters grown to a size of 100 to 150 mum contained cells staining for stage-specific embryonic antigens, but not insulin or C-peptide. To direct cell differentiation toward islets, clusters were recultured in a pancreatic differentiation medium. Insulin and C-peptide-positive cells by immunocytochemistry appeared within a week, reaching over 10% of the cell population. Glucagon and somatostatin-positive cells were also detected. The cell clusters were found to secrete insulin in response to glucose stimulation. Cells from the same clusters also had the capacity for differentiation into neural cells, as documented by staining for neural and glial cell markers when cultured as monolayers in media containing neurotrophic factors. These data suggest that multipotent pancreatic progenitor cells exist within the human pancreatic tissue that is typically discarded during islet isolation procedures. These adult progenitor cells can be successfully differentiated into insulin-producing cells, and thus they have the potential for treatment of type-1 diabetes mellitus.
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Tajima T, Watanabe N, Kogawa Y, Takiguchi N, Kato J, Ikeda T, Kuroda A, Ohtake H. Chemotaxis of the nematode Caenorhabditis elegans toward cycloheximide and quinine hydrochloride. J Biosci Bioeng 2005; 91:322-4. [PMID: 16232999 DOI: 10.1263/jbb.91.322] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2000] [Accepted: 12/25/2000] [Indexed: 11/17/2022]
Abstract
We investigated the chemotaxis of the nematode Caenorhabditis elegans toward cycloheximide, denatonium benzoate, 6-n-propyl-2-thiouracil, and quinine hydrochloride. Interestingly, C. elegans was strongly attracted to cycloheximide, while avoiding quinine hydrochloride. This is the first report thus far to describe the chemotactic responses of C. elegans toward bitter tastants for humans.
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Wu H, Kosaka H, Kato J, Kuroda A, Ikeda T, Takiguchi N, Ohtake H. Cloning and characterization of Pseudomonas putida genes encoding the phosphate-specific transport system. J Biosci Bioeng 2005; 87:273-9. [PMID: 16232467 DOI: 10.1016/s1389-1723(99)80031-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/1998] [Accepted: 11/27/1998] [Indexed: 11/20/2022]
Abstract
The pstSCAB genes of Pseudomonas putida PRS2000, encoding the phosphate (Pi)-specific transport (Pst) system, were cloned. The pstS gene of Pseudomonas aeruginosa PAO1, of which the pstCAB genes had been cloned previously, was also cloned (Nikata, T. et al., Mol. Gen. Genet., 250, 692-698, 1996). The predicted translation products of the P. putida pstSCAB genes showed 83, 75, 78 and 88% amino acid identity with their P. aeruginosa counterparts. Two well-conserved Pho box sequences were found in the region upstream of the pstS gene (15/18 base identity with the consensus Pho box sequence) and in the intercistronic region between the pstS and pstC genes (11/18 base identity) of P. putida PRS2000. To investigate the functions of PstSCAB, the pstSC genes were inactivated by inserting a kanamycin resistance gene cassette into the chromosome of P. putida PRS2000. The resultant mutant, designated PNT1, failed to take up 32Pi even under conditions of Pi limitation. Strain PNT1 was also constitutive for alkaline phosphatase synthesis, as well as chemotaxis toward Pi, indicating that the Pst system is involved in the negative regulation of the pho regulon in P. putida. Although overexpression of the pstSCAB genes in P. putida PRS2000 resulted in decreased cell growth, this recombinant strain could remove Pi at a rate similar to that seen with the control strain.
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Kuroda A, Kunimoto H, Morohoshi T, Ikeda T, Kato J, Takiguchi N, Miya A, Ohtake H. Evaluation of phosphate removal from water by immobilized phosphate-binding protein PstS. J Biosci Bioeng 2005; 90:688-90. [PMID: 16232935 DOI: 10.1263/jbb.90.688] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2000] [Accepted: 10/02/2000] [Indexed: 11/17/2022]
Abstract
The phosphate (P(i))-binding protein PstS is a member of a family of periplasmic proteins that act as high-affinity receptors for active transport systems in bacteria. PstS protein purified from Pseudomonas aeruginosa was immobilized to N-hydroxysuccinimide-activated Sepharose, packed into a plastic column (5 x 70 mm), and examined for its potential ability to remove P(i) from water. The PstS-Sepharose column completely removed P(i) from 32P-labeled pond water containing about 0.5 microM P(i) (0.015 mg P per liter). More than 90% of 32P-P(i) that was retained in the column could be eluted by washing with low-pH water.
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Kuroda A, Kaneto H, Fujitani Y, Watada H, Nakatani Y, Kajimoto Y, Matsuhisa M, Yamasakai Y, Fujiwara M. Mutation of the Pax6 gene causes impaired glucose-stimulated insulin secretion. Diabetologia 2004; 47:2039-41. [PMID: 15565366 DOI: 10.1007/s00125-004-1563-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2004] [Accepted: 09/15/2004] [Indexed: 10/26/2022]
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Kuroda A, Iyanagi H. A novel polymer anti-irritant barrier film for cosmetics. Int J Cosmet Sci 2004. [DOI: 10.1111/j.1467-2494.2004.00224_4.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Hosogai N, Hamada K, Tomita M, Nagashima A, Takahashi T, Sekizawa T, Mizutani T, Urano Y, Kuroda A, Sawada K, Ozaki T, Seki J, Goto T. FR226807: a potent and selective phosphodiesterase type 5 inhibitor. Eur J Pharmacol 2001; 428:295-302. [PMID: 11675048 DOI: 10.1016/s0014-2999(01)01345-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We describe the pharmacological characteristics of a novel phosphodiesterase type 5 inhibitor FR226807, N-(3,4-dimethoxybenzyl)-2-[[(1R)-2-hydroxy-1-methylethyl]amino]-5-nitrobenzamide. FR226807 inhibited phosphodiesterase type 5 isolated from human platelets with an IC(50) value of 1.1 nM. FR226807 also inhibited phosphodiesterase type 6 with an IC(50) of 20 nM; however, the IC(50) value for phosphodiesterase type 6 was 18-fold higher than that for phosphodiesterase type 5. The IC(50) values of FR226807 for other phosphodiesterases (phosphodiesterase type 1, phosphodiesterase type 2, phosphodiesterase type 3, and phosphodiesterase type 4) were 1000-fold higher than that for phosphodiesterase type 5. FR226807 increased the cyclic guanosine monophosphate (cGMP) content in corpus cavernosum isolated from rabbit, an effect associated with relaxation of the muscle. FR226807 enhanced the relaxation response induced by electrical field stimulation of corpus cavernosum isolated from the rabbit. In an anesthetized dog model for the evaluation of erectile function, intravenous administration of FR226807 prolonged the time to return to 75% of maximal intracavernosal pressure after cessation of electrical stimulation of the pelvic nerve. In summary, FR226807 is a potent and highly selective phosphodiesterase type 5 inhibitor with an augmentative effect on penile erection and will be useful for the treatment of erectile dysfunction.
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Kuroda A, Nomura K, Ohtomo R, Kato J, Ikeda T, Takiguchi N, Ohtake H, Kornberg A. Role of inorganic polyphosphate in promoting ribosomal protein degradation by the Lon protease in E. coli. Science 2001; 293:705-8. [PMID: 11474114 DOI: 10.1126/science.1061315] [Citation(s) in RCA: 274] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Inorganic polyphosphate (polyP), a polymer of hundreds of phosphate (Pi) residues, accumulates in Escherichia coli in response to stresses, including amino acid starvation. Here we show that the adenosine 5'-triphosphate-dependent protease Lon formed a complex with polyP and degraded most of the ribosomal proteins, including S2, L9, and L13. Purified S2 also bound to polyP and formed a complex with Lon in the presence of polyP. Thus, polyP may promote ribosomal protein degradation by the Lon protease, thereby supplying the amino acids needed to respond to starvation.
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Sawada K, Okada S, Kuroda A, Watanabe S, Sawada Y, Tanaka H. 4-(Benzoylindolizinyl)butyric acids; novel nonsteroidal inhibitors of steroid 5alpha-reductase. III. Chem Pharm Bull (Tokyo) 2001; 49:799-813. [PMID: 11456083 DOI: 10.1248/cpb.49.799] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A novel series of indolizinebutyric acids with various benzoyl substituents was synthesized to develop nonsteroidal inhibitors of steroid 5alpha-reductase, and the structure-activity relationships in this series were studied. We previously reported the structure-activity relationships in a series of indolebutyric acids as well as the discovery of the novel nonsteroidal 5alpha-reductase inhibitor, FK143. We have now made other modifications to this compound to improve in vivo inhibitory activity. By altering the heterocyclic nucleus and changing the benzoyl substituent we have succeeded in identifying the strongly active compound, FK687, (S)-4-[1-[4-[[1-(4-isobutylphenyl)butyl]oxy]benzoyl]indolizin-3-yl]butyric acid, which displays strong in vitro inhibitory activity against the human enzyme and in vivo inhibitory activity against the castrated young rat model. This compound should be a useful agent for the treatment of benign prostatic hyperplasia.
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Inagawa H, Kuroda A, Nishizawa T, Honda T, Ototake M, Yokomizo U, Nakanishi T, Soma G. Cloning and characterisation of tandem-repeat type galectin in rainbow trout (Oncorhynchus mykiss). FISH & SHELLFISH IMMUNOLOGY 2001; 11:217-231. [PMID: 11394689 DOI: 10.1006/fsim.2000.0307] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Fish beta-galactoside binding lectin (galectin) cDNA was cloned from the cDNA library of rainbow trout (Oncorhynchus mykiss) head kidney. The clone contained a single open reading frame encoding 341 amino acids (aa) (38 kDa protein), including the initiator methionine. Significant sequence homology to mammalian galectin-9 (40-55% identity) was observed. Its amino acid sequence showed two distinct N- and C-terminal domains (148 and 130 aa, respectively) connected by a peptide linker (63 aa). The galectin contains two consensus WG-E-R/K motifs thought to play an essential role in sugar-binding, indicating that this lectin is a member of the tandem-repeat type galectins which have not been identified in fish. The 1.6 kDa mRNA of the lectin was found by Northern blot analyses to be widely expressed in the spleen, head kidney, thymus, peritoneal exudate cells, ovary, gills and heart. Southern blot analyses with the probe for C-terminal of the lectin showed the existence of two hybridising genes. These results suggest that rainbow trout has at least one tandem-repeat type galectin as well as proto-type galectin.
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Kato J, Nagata C, Yang L, Kuroda A, Ikeda T, Takiguchi N, Ohtake H. Isolation and characterization of the Enterobacter cloacae cheR mutant defective in phosphate taxis. Biosci Biotechnol Biochem 2001; 65:456-8. [PMID: 11302189 DOI: 10.1271/bbb.65.456] [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: 11/08/2022]
Abstract
A chemotaxis-defective mutant of Enterobacter cloacae IFO3320, designated EC1, was isolated after N-methyl-N'-nitro-N-nitrosoguanidine (NTG) mutagenesis. Computer-assisted capillary assays showed that EC1 failed to show chemotactic responses to peptone and inorganic phosphate (Pi). Cloning and sequence analysis showed that EC1 is a cheR mutant, suggesting that Pi taxis by E. cloacae is dependent on a methyl-accepting chemotaxis protein(s) (MCP). EC1 was further mutagenized with NTG to construct cheR pstS and cheR pstA double mutants. A recombinant plasmid pECT01.2, which contained the E. cloacae cheR gene, restored the ability of these double mutants to show chemotaxis toward peptone but not Pi. These results suggest that the phosphate-specific transport (Pst) system, together with a MCP(s), is required for detecting Pi in E. cloacae.
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Nanashima A, Yamaguchi H, Fukuda T, Sakamoto I, Kuroda A, Sawai T, Nakagoe T, Ayabe H. Evaluation of pancreatic secretion after administration of secretin: application of magnetic resonance imaging. J Gastroenterol Hepatol 2001; 16:87-92. [PMID: 11206321 DOI: 10.1046/j.1440-1746.2001.02391.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
BACKGROUND To evaluate pancreatic exocrine function, we measured the changes in T2 enhanced hydrograhic intensity on magnetic resonance (MR) images of the pancreas following an injection of secretin, which is representative of the changes in duodenal fluid volume. METHODS The subjects were 10 patients with normal pancreatic function (N > 70% detected by using a pancreatic function diagnostant test) and 12 patients with hypo-function, including those with mild hypo-function (MH, 50-70%, six patients) and severe hypo-function (SH < 50%, six patients). RESULTS In the N group, T2 enhanced intensity of the pancreas increased to a maximum value (more than 10% compared with baseline) within 5 min of stimulation, then gradually decreased. No significant difference in the response was observed between the head and body of the pancreas. Changes in the MH group were similar to those of the N group. In contrast, significantly lower changes in T2 enhanced intensity were observed in SH group, relative to both the N and MH group (P < 0.05). The amount of secretin-induced increase in duodenal fluid after 16 min was not significantly different among the three groups. Furthermore, an evaluation of the residual pancreatic tissue after a pancreatoduodenectomy was also feasible. CONCLUSIONS Our results indicate that the MR-secretin test is useful for the evaluation of severe pancreatic exocrine dysfunction. The diagnostic test is simple, direct and non-invasive.
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Lee SO, Kato J, Takiguchi N, Kuroda A, Ikeda T, Mitsutani A, Ohtake H. Involvement of an extracellular protease in algicidal activity of the marine bacterium Pseudoalteromonas sp. strain A28. Appl Environ Microbiol 2000; 66:4334-9. [PMID: 11010878 PMCID: PMC92304 DOI: 10.1128/aem.66.10.4334-4339.2000] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The marine bacterium Pseudoalteromonas sp. strain A28 was able to kill the diatom Skeletonema costatum strain NIES-324. The culture supernatant of strain A28 showed potent algicidal activity when it was applied to a paper disk placed on a lawn of S. costatum NIES-324. The condensed supernatant, which was prepared by subjecting the A28 culture supernatant to ultrafiltration with a 10,000-M(w)-cutoff membrane, showed algicidal activity, suggesting that strain A28 produced extracellular substances capable of killing S. costatum cells. The condensed supernatant was then found to have protease and DNase activities. Two Pseudoalteromonas mutants lacking algicidal activity, designated NH1 and NH2, were selected after N-methyl-N'-nitrosoguanidine mutagenesis. The culture supernatants of NH1 and NH2 showed less than 15% of the protease activity detected with the parental strain, A28. The protease was purified to homogeneity from A28 culture supernatants by using ion-exchange chromatography followed by preparative gel electrophoresis. Paper-disk assays revealed that the purified protease had potent algicidal activity. The purified protease had a molecular mass for 50 kDa, and the N-terminal amino acid sequence was determined to be Ala-Thr-Pro-Asn-Asp-Pro. The optimum pH and temperature of the protease were found to be 8.8 and 30 degrees C, respectively, by using succinyl-Ala-Ala-Pro-Phe-p-nitroanilide as a substrate. The protease activity was strongly inhibited by phenylmethylsulfonyl fluoride, diisopropyl fluorophosphate, antipain, chymostatin, and leupeptin. No significant inhibition was detected with EDTA, EGTA, phenanthroline or tetraethylenepentamine. These results suggest that Pseudoalteromonas sp. strain A28 produced an extracellular serine protease which was responsible for the algicidal activity of this marine bacterium.
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Yamagata A, Hirota R, Kato J, Kuroda A, Ikeda T, Takiguchi N, Ohtake H. Mutational analysis of the multicopy hao gene coding for hydroxylamine oxidoreductase in Nitrosomonas sp. strain ENI-11. Biosci Biotechnol Biochem 2000; 64:1754-7. [PMID: 10993170 DOI: 10.1271/bbb.64.1754] [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: 11/08/2022]
Abstract
The ammonia-oxidizing bacterium Nitrosomonas sp. strain ENI-11 contains three copies of the hao gene (hao1, hao2, and hao3) coding for hydroxylamine oxidoreductase (HAO). Three single mutants (hao1::kan, hao2::kan, or hao3::kan) had 68 to 75% of the wild-type growth rate and 58 to 89% of the wild-type HAO activity when grown under the same conditions. A double mutant (hao1::kan and hao3::amp) also had 68% of the wild-type growth and 37% of the wild-type HAO activity.
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Taki H, Sugiyama E, Kuroda A, Mino T, Kobayashi M. Interleukin-4 inhibits interleukin-11 production by rheumatoid synovial cells. Rheumatology (Oxford) 2000; 39:728-31. [PMID: 10908690 DOI: 10.1093/rheumatology/39.7.728] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVE To examine the effect of interleukin-4 (IL-4) on IL-11 production by rheumatoid synovial cells. METHODS Freshly isolated rheumatoid synovial cells (FRS) were obtained by collagenase digestion of rheumatoid arthritis (RA) synovial tissue specimens taken at the time of operation. Rheumatoid synovial cells at four to eight passages were used as cultured rheumatoid synovial fibroblasts (RSF). IL-11 concentration was measured by ELISA. RESULTS IL-4 inhibited the production of IL-11 by FRS in a dose-dependent manner. This inhibition was observed in FRS obtained from six patients, and the mean inhibition was 46.5%. The inhibitory effect of IL-4 on IL-11 production was cancelled by the addition of anti-IL-4 antibody. IL-4 also inhibited IL-11 production by IL-1alpha-stimulated cultured RSF. CONCLUSION IL-4 inhibited IL-11 production by rheumatoid synovial cells. IL-4 has a protective effect on bone resorption. On the contrary, IL-11 participates in bone resorption via osteoclastogenesis. Therefore, IL-4 may exert its protective effect on bone resorption, at least in part, via inhibition of IL-11 production in rheumatoid joints.
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Wu H, Kato J, Kuroda A, Ikeda T, Takiguchi N, Ohtake H. Identification and characterization of two chemotactic transducers for inorganic phosphate in Pseudomonas aeruginosa. J Bacteriol 2000; 182:3400-4. [PMID: 10852870 PMCID: PMC101905 DOI: 10.1128/jb.182.12.3400-3404.2000] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Two chemotactic transducers for inorganic phosphate (P(i)), designated CtpH and CtpL, have been identified in Pseudomonas aeruginosa. The corresponding genes (ctpH and ctpL) were inactivated by inserting kanamycin and tetracycline resistance gene cassettes into the wild-type genes in the P. aeruginosa PAO1 genome. Computer-assisted capillary assays showed that the ctpH single mutant failed to exhibit P(i) taxis when the concentration of P(i) in the capillary was higher than 5 mM. Conversely, the ctpL single mutant could not respond to P(i) at the concentration of 0.01 mM. The ctpH ctpL double mutant was defective in P(i) taxis at any concentration ranging from 0.01 to 10 mM. To investigate regulation of P(i) taxis, the ctpH and ctpL genes were also disrupted individually in the P. aeruginosa phoU and phoB single mutants. The ctpH phoU and ctpH phoB double mutants were defective in P(i) taxis, regardless of whether the cells were starved for P(i). The ctpL phoU double mutant was constitutive for P(i) taxis, whereas the ctpL phoB double mutant was induced by P(i) limitation for P(i) taxis. The region upstream of ctpL, but not ctpH, contained a putative pho box sequence. Expression of ctpL::lacZ was induced by P(i) limitation in PAO1, while it was constitutive in the phoU mutant. In contrast, the phoB mutant showed only background levels of ctpL::lacZ expression. These results showed that ctpL is involved in the pho regulon genes in P. aeruginosa. The ctpH phoU mutant, which failed to exhibit P(i) taxis, was constitutive for ctpL::lacZ expression, suggesting that the P(i) detection by CtpL requires PhoU. Like PAO1, the phoB and phoU single mutants were constitutive for expression of ctpH::lacZ. Thus, the evidence that the ctpL phoU mutant, but not the ctpL phoB mutant and PAO1, was constitutive for P(i) taxis raised the possibility that PhoU exerts a negative control on P(i) detection by CtpH at the posttranscriptional level.
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Kuroda A, Ohtake H. Molecular analysis of polyphosphate accumulation in bacteria. BIOCHEMISTRY. BIOKHIMIIA 2000; 65:304-8. [PMID: 10739472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The dynamic behavior of inorganic polyphosphate (polyP), its accumulation and disappearance, is the most striking aspect of polyP metabolism in bacteria. Imbalance between polyP synthesis and degradation results in fluctuations of polyP by 100- to 1000-fold. We here review recent results with respect to this polyP metabolism in bacteria. PolyP accumulation in response to amino acid starvation, accompanied by increased levels of stringent factors, has been observed in Escherichia coli. Inhibition by stringent factors of polyphosphatase interrupts the dynamic balance between the synthesis and degradation of polyP, accounting for polyP accumulation. Polyphosphate kinase is required for activation of intracellular protein degradation, which is required for adaptation at the onset of amino acid starvation. The adaptation to amino acid starvation is mediated by the network of stringent response and polyP metabolism. PolyP accumulation independent of stringent response has also been observed. Novobiocin, an inhibitor for DNA gyrase, stimulated accumulation of polyP but not that of stringent factors. However, a temperature-sensitive DNA gyrase mutant did not exhibit polyP accumulation at the non-permissive temperature. Antagonistic relationship of polyP to nucleic acid synthesis, explored by Harold, appears to be more complicated. We discuss relationship of Pi regulation to polyP accumulation in E. coli and Klebsiella aerogenes. A function of polyP as an in vivo phosphagen affecting polyP accumulation is also discussed.
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Hirota R, Yamagata A, Kato J, Kuroda A, Ikeda T, Takiguchi N, Ohtake H. Physical map location of the multicopy genes coding for ammonia monooxygenase and hydroxylamine oxidoreductase in the ammonia-oxidizing bacterium Nitrosomonas sp. strain ENI-11. J Bacteriol 2000; 182:825-8. [PMID: 10633121 PMCID: PMC94350 DOI: 10.1128/jb.182.3.825-828.2000] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pulsed-field gel electrophoresis of PmeI digests of the Nitrosomonas sp. strain ENI-11 chromosome produced four bands ranging from 1,200 to 480 kb in size. Southern hybridizations suggested that a 487-kb PmeI fragment contained two copies of the amoCAB genes, coding for ammonia monooxygenase (designated amoCAB(1) and amoCAB(2)), and three copies of the hao gene, coding for hydroxylamine oxidoreductase (hao(1), hao(2), and hao(3)). In this DNA fragment, amoCAB(1) and amoCAB(2) were about 390 kb apart, while hao(1), hao(2), and hao(3) were separated by at least about 100 kb from each other. Interestingly, hao(1) and hao(2) were located relatively close to amoCAB(1) and amoCAB(2), respectively. DNA sequence analysis revealed that hao(1) and hao(2) shared 160 identical nucleotides immediately upstream of each translation initiation codon. However, hao(3) showed only 30% nucleotide identity in the 160-bp corresponding region.
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Matsuhisa M, Yamasaki Y, Shiba Y, Nakahara I, Kuroda A, Tomita T, Iida M, Ikeda M, Kajimoto Y, Kubota M, Hori M. Important role of the hepatic vagus nerve in glucose uptake and production by the liver. Metabolism 2000; 49:11-6. [PMID: 10647058 DOI: 10.1016/s0026-0495(00)90538-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We examined the role of the hepatic vagus nerve in hepatic and peripheral glucose metabolism. To assess endogenous glucose production (EGP), hepatic uptake of first-pass glucose infused intraportally (HGU), and the metabolic clearance rate of glucose (MCR), rats were subjected to hepatic vagotomy (HV, n = 7) or sham operation (SH, n = 8), after 10 days, they were then subjected to a euglycemic-hyperinsulinemic clamp together with a portal glucose load in the 24-hour fasting state. Metabolic parameters were determined by the dual-tracer method using stable isotopes. During the experiment, [6,6-2H2]glucose was continuously infused into the peripheral vein. To maintain euglycemia (4.5 mmol/L), insulin (54 pmol x kg(-1) x min(-1)) and glucose were infused peripherally after the 90-minute tracer equilibration and 30-minute basal periods, and glucose containing 5% enriched [U-13C]glucose was infused intraportally (50 micromol x kg(-1) x min(-1)) for 120 minutes (clamp period). EGP was significantly higher in HV rats versus SH rats during the basal period (64.3 +/- 7.6 v 43.6 +/- 5.3 micromol x kg(-1) x min(-1), P < .005)) and was comparable to EGP in SH rats during the clamp period (9.3 +/- 21.5 v 1.1 +/- 11.7 micromol x kg(-1) x min(-1)). HGU was reduced in HV rats compared with SH rats during portal glucose infusion (5.9 +/- 2.4 v 10.1 +/- 3.2 micromol x kg(-1) x min(-1)). The MCR in HV rats was significantly higher than in SH rats in the basal period (11.0 +/- 2.0 v 7.9 +/- 0.8 mL x kg(-1) x min(-1), P < .01)) and was comparable to the MCR in SH rats during the clamp period (41.9 +/- 10.0 and 36.6 +/- 5.7 mL x kg(-1) x min(-1)). We conclude that innervation of the hepatic vagus nerve is important for the regulation of hepatic glucose production in the postabsorptive state and HGU in the postprandial state.
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Kuroda A, Tanaka S, Ikeda T, Kato J, Takiguchi N, Ohtake H. Inorganic polyphosphate kinase is required to stimulate protein degradation and for adaptation to amino acid starvation in Escherichia coli. Proc Natl Acad Sci U S A 1999; 96:14264-9. [PMID: 10588694 PMCID: PMC24425 DOI: 10.1073/pnas.96.25.14264] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Inorganic polyphosphate (polyP) kinase was studied for its roles in physiological responses to nutritional deprivation in Escherichia coli. A mutant lacking polyP kinase exhibited an extended lag phase of growth, when shifted from a rich to a minimal medium (nutritional downshift). Supplementation of amino acids to the minimal medium abolished the extended growth lag of the mutant. Levels of the stringent response factor, guanosine 5'-diphosphate 3'-diphosphate, increased in response to the nutritional downshift, but, unlike in the wild type, the levels were sustained in the mutant. These results suggested that the mutant was impaired in the induction of amino acid biosynthetic enzymes. The expression of an amino acid biosynthetic gene, hisG, was examined by using a transcriptional lacZ fusion. Although the mutant did not express the fusion in response to the nutritional downshift, Northern blot analysis revealed a significant increase of hisG-lacZ mRNA. Amino acids generated by intracellular protein degradation are very important for the synthesis of enzymes at the onset of starvation. In the wild type, the rate of protein degradation increased in response to the nutritional downshift whereas it did not in the mutant. Supplementation of amino acids at low concentrations to the minimal medium enabled the mutant to express the hisG-lacZ fusion. Thus, the impaired regulation of protein degradation results in the adaptation defect, suggesting that polyP kinase is required to stimulate protein degradation.
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Marusawa H, Setoi H, Kuroda A, Sawada A, Seki J, Motoyama Y, Tanaka H. Synthesis and biological activity of 4-methyl-3,5-dioxane derivatives as thromboxane A2 receptor antagonists. Bioorg Med Chem 1999; 7:2635-45. [PMID: 10632075 DOI: 10.1016/s0968-0896(99)00204-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The synthesis and biological activity of novel 4-methyl-3,5-dioxane analogues are described. All compounds were produced through modification of the substituent formally corresponding to the omega-octenol side chain of thromboxane A2 (TXA2), in reference to the structure of SQ29548. Several compounds were found to be potent TXA2 receptor antagonists. Compound 8b was the most effective inhibitor of 9,11-epoxymethano PGH2 (U-46619)-induced human platelet aggregation (IC50 = 7.4 nM).
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Abstract
BACKGROUND The aim of this study was to establish an optimal management strategy for pancreatic disorders associated with anomalous pancreaticobiliary junction (APBJ). METHODS In 64 adult surgical cases of APBJ (common channel 15 mm or longer) (43 with and 21 without choledochal cyst), associated pancreatic disorders, pancreatographic results, and treatment outcomes were analyzed. RESULTS Of 64 patients, 56 had pancreatobiliary symptoms. Twenty-four patients (38%) had pancreatic disorders: acute pancreatitis (n = 20), chronic calcifying pancreatitis (n = 2), and pancreatic carcinoma (n = 2). Twenty patients (31%) had abnormal pancreatograms. The incidence of acute pancreatitis was significantly higher in patients with an abnormal pancreatogram, particularly dilatation, protein plugs or stones of the common channel or main pancreatic duct, and coexisting pancreatic ductal anomaly. All patients with choledochal cyst underwent cyst excision and hepaticojejunostomy. Eleven patients without choledochal cyst or pancreatobiliary carcinoma underwent cholecystectomy alone. Protein plugs and pancreatic stones were extracted through the bile duct stump or by sphincterotomy. No patients experienced pancreatitis during a mean postoperative follow-up of 6.7 years. CONCLUSIONS In managing APBJ, attention should be paid to the possibility of associated pancreatic disorders and an abnormal pancreatogram. APBJ with choledochal cyst requires cyst excision. Cholecystectomy alone may be adequate for APBJ without cyst.
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Ohtake H, Kuroda A, Kato J, Ikeda T. Genetic improvement of bacteria for enhanced biological removal of phosphate from wastewater. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 1999; 23:299-311. [PMID: 10448683 DOI: 10.1007/978-3-642-58444-2_15] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
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