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Morisawa N, Koshima Y, Kuriyama S, Matsuyama M, Hayashi N, Satoh JI, Amemiya M, Yokoo T. Effectiveness of a fixed combination formula of ombitasvir/paritaprevir/ritonavir for hepatitis C virus infection in patients on maintenance haemodialysis. Nephrology (Carlton) 2018. [PMID: 28621007 DOI: 10.1111/nep.13011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
A fixed-dose formula that combines Ombitasvir (OBV), Paritaprevir (PTV) and Ritonavir (RTV) has been launched into the field of anti-HCV therapy in Japan for patients infected with HCV genotypes 1 and 2 in 2015. However, little is yet known as to the efficacy and safety of this novel therapy in patients on maintenance haemodialysis (HD). The present report describes a preliminary experience in 10 patients (five males and five females) who underwent maintenance HD. All of them had HCV genotype 1b, without having the resistance-associated variants at Y93 or L31 in the nonstructural proteins 5A (NS5A) region. After the treatment, eight patients successfully achieved virus eradication and sustained a virological response at 12 weeks (SVR12). In addition, mac-2 binding protein glycosylation isomer (M2BPGi), a biomarker for liver fibrosis, was reduced after the therapy. Two patients withdrew from the therapy due to the development of erythema multiforme and a strong drowsiness, respectively. These results suggest that triple therapy combining OBV, PTV and RTV is effective in achieving SVR12 in most of the HCV-infected patients on HD. In addition, this combination therapy contributed to retard the progression of liver fibrosis. However, we suggest that further trial will be required to establish its clinical efficacy and safety.
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Affiliation(s)
- Norihiko Morisawa
- Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan.,Division of Nephrology, Department of Internal Medicine, Saitama Red Cross Hospital, Saitama, Japan
| | - Yohei Koshima
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Saitama Red Cross Hospital, Saitama, Japan
| | - Satoru Kuriyama
- Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan
| | - Momoko Matsuyama
- Division of Nephrology, Department of Internal Medicine, Saitama Red Cross Hospital, Saitama, Japan
| | - Naomi Hayashi
- Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan.,Division of Nephrology, Department of Internal Medicine, Saitama Red Cross Hospital, Saitama, Japan
| | - Jun-Ichi Satoh
- Division of Nephrology, Department of Internal Medicine, Saitama Red Cross Hospital, Saitama, Japan
| | - Morimasa Amemiya
- Division of Nephrology, Department of Internal Medicine, Saitama Red Cross Hospital, Saitama, Japan
| | - Takashi Yokoo
- Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan
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Iiya M, Shimizu M, Taomoto Y, Amemiya M, Sato Y, Yamakami Y, Nakamura R, Nakano K, Shimada H, Fujii H, Yamawake N, Nishizaki M. P6431Impact of hemoglobin level for prediction of neurological-full-recovery in patients with out-of-hospital-cardiac-arrest after return-of-spontaneous-circulation. Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx493.p6431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Sato Y, Shimizu M, Taomoto Y, Amemiya M, Iiya M, Yamakami Y, Nakamura R, Nakano K, Shimada H, Fujii H, Yamawake N, Nishizaki M, Sakurada H, Hiraoka M. P6427The prognostic value of high-frequency component in holter electrocardiograms on lethal arrhythmia in patients with vasospastic angina. Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx493.p6427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Shimizu M, Taomoto Y, Amemiya M, Yamakami Y, Sato Y, Iiya M, Nakamura R, Nakano K, Shimada H, Fujii H, Yamawake N, Nishizaki M, Sakurada H, Hiraoka M. P881Diagnostic performance of T-axis deviation on 12-leads electrocardiography for myocardial ischemia: Analysis by semiconductor SPECT. Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx501.p881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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5
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Shimizu M, Taomoto Y, Amemiya M, Yamakami Y, Sato Y, Iiya M, Nakamura R, Nakano K, Shimada H, Fujii H, Yamawake N, Nishizaki M, Sakurada H, Hiraoka M. P1458Prognostic value of T wave axis deviation for left ventricular dysfunction in patients with complete left bundle branch block. Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx502.p1458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Morisawa N, Satoh H, Matsuyama M, Hayashi N, Adachi A, Satoh JI, Yokoo T, Amemiya M. [Usefulness of the treatment with corticosteroids and ciclosporin A for TAFRO syndrome]. Nihon Naika Gakkai Zasshi 2016; 105:2432-2439. [PMID: 30646443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
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Onuigbo M, Agbasi N, Wu MJ, Shu KH, Kugler E, Cohen E, Krause I, Goldberg E, Garty M, Krause I, Jansen J, De Napoli IE, Schophuizen CM, Wilmer MJ, Mutsaers HA, Heuvel LP, Grijpma DW, Stamatialis D, Hoenderop JG, Masereeuw R, Van Craenenbroeck AH, Van Craenenbroeck EM, Van Ackeren K, Vrints CJ, Hoymans VY, Couttenye MM, Erkmen Uyar M, Tutal E, Bal Z, Guliyev O, Sezer S, Liu L, Wang C, Tanaka K, Kushiyama A, Sakai K, Hara S, Ubara Y, Ohashi Y, Kunugi Y, Kawazu S, Untersteller K, Seiler S, Rogacev KS, Emrich IE, Lennartz CS, Fliser D, Heine GH, Hoshino T, Ookawara S, Miyazawa H, Ueda Y, Ito K, Kaku Y, Hirai K, Mori H, Yoshida I, Kakuta S, Hayama N, Amemiya M, Okamoto H, Inoue S, Tabei K, Campos P, Dias C, Baptista J, Papoila AL, Ortiz A, Inchaustegui L, Soto K, Moon KH, Yang S, Lee DY, Kim HW, Kim B, Isnard Bagnis C, Guerraoui A, Zenasni F, Idier L, Chauveau P, Cerqueira A, Quelhas-Santos J, Pestana M, Choi JY, Jin DC, Choi YJ, Kim WY, Nam SA, Cha JH, Cernaro V, Loddo S, Lacquaniti A, Romeo A, Costantino G, Montalto G, Santoro D, Trimboli D, Ricciardi CA, Lacava V, Buemi M, Emrich IE, Zawada AM, Rogacev KS, Seiler S, Obeid R, Geisel J, Fliser D, Heine GH, Meneses GC, Silva Junior G, Costa MFB, Goncalves HS, Daher EF, Liborio AB, Martins AMC, Ekart R, Hojs N, Bevc S, Hojs R, Lim CS, Hwang JH, Chin HJ, Kim S, Kim DK, Kim S, Park JH, Shin SJ, Lee SH, Choi BS, Lemoine S, Panaye M, Juillard L, Dubourg L, Hadj-Aissa A, Guebre-Egziabher F, Silva Junior G, Vieira APF, Couto Bem AX, Alves MP, Meneses GC, Martins AMC, Liborio AB, Daher EF, Ito K, Ookawara S, Miyazawa H, Ueda Y, Kaku Y, Hirai K, Hoshino T, Mori H, Yoshida I, Tabei K, Stefan G, Capusa C, Stancu S, Margarit D, Petrescu L, Nedelcu ED, Mircescu G, Szarejko-Paradowska A, Rysz J, Hung CC, Chen HC, Ristovska V, Grcevska L, Podesta MA, Reggiani F, Cucchiari D, Badalamenti S, Buemi M, Ponticelli C, Graziani G, Nouri-Majalan N, Moghadasimousavi S, Eshaghyeh Z, Greenwood S, Koufaki P, Maclaughlin H, Rush R, Hendry BM, Macdougall IC, Mercer T, Cairns H. CKD LAB METHODS, PROGRESSION & RISK FACTORS 2. Nephrol Dial Transplant 2014. [DOI: 10.1093/ndt/gfu165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
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Kamishima T, Kitamura N, Amemiya M, Ishizaka K, Kato F, Yasuda K, Shirato H, Terae S. Experimental MR imaging of zirconia ceramic joint implants at 1.5 and 3 T. Clin Radiol 2010; 65:387-90. [DOI: 10.1016/j.crad.2009.12.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2009] [Revised: 12/04/2009] [Accepted: 12/07/2009] [Indexed: 11/29/2022]
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Hong FL, Musha M, Takamoto M, Inaba H, Yanagimachi S, Takamizawa A, Watabe K, Ikegami T, Imae M, Fujii Y, Amemiya M, Nakagawa K, Ueda K, Katori H. Measuring the frequency of a Sr optical lattice clock using a 120 km coherent optical transfer. Opt Lett 2009; 34:692-694. [PMID: 19252595 DOI: 10.1364/ol.34.000692] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We demonstrate a precision frequency measurement using a phase-stabilized 120 km optical fiber link over a physical distance of 50 km. The transition frequency of the (87)Sr optical lattice clock at the University of Tokyo is measured to be 429228004229874.1(2.4) Hz referenced to international atomic time. The results demonstrate the excellent functions of the intercity optical fiber link and the great potential of optical lattice clocks for use in the redefinition of the second.
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Affiliation(s)
- F-L Hong
- National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technologies, Tsukuba, Ibaraki, Japan.
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Abstract
We evaluated the use of hydroxyapatite blocks as spacers in pelvic osteotomy. The hydroxyapatite blocks fused with autologous bone tissue within 10 months and were highly biocompatible even after 10 years. They prevent pelvic deformities and are as effective as autogenous bone grafts.
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Affiliation(s)
- M Amemiya
- Department of Orthopedics, Jichi Children's Medical Center, Jichi Medical University, Tochigi, Japan.
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Ikebe K, Amemiya M, Morii K, Matsuda K, Furuya-Yoshinaka M, Nokubi T. Comparison of oral stereognosis in relation to age and the use of complete dentures. J Oral Rehabil 2007; 34:345-50. [PMID: 17441875 DOI: 10.1111/j.1365-2842.2007.01687.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The purpose of this study was to examine the age-related difference in oral sensory function by testing oral stereognostic ability (OSA) and to determine the effect of wearing complete dentures on OSA. Subjects were 20 dentate and 30 edentulous elderly patients free from oral symptoms and pathologies, and 30 younger dentate students as controls. The OSA tests were conducted with test pieces of 12 shaped forms. The duration time for recognition was noted and the answers were recorded using a three-point scale. anova and paired t-tests were used to examine significant differences. P-values <0.05 were considered to be statistically significant. The OSA score in older dentate participants and complete denture wearers was significantly higher than in younger dentate subjects. However, no significant difference was found in the OSA score between older dentate participants and complete denture wearers. When older edentulous subjects removed the maxillary and mandible complete dentures, the OSA score was significantly lower and the response time significantly longer than with dentures. Within the limitations of this study, an age-related difference in oral sensory function, as measured by OSA tests, was found. However, oral sensory function was not significantly different between fully dentate persons and complete denture wearers in the elderly.
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Affiliation(s)
- K Ikebe
- Division of Oromaxillofacial Regeneration, Osaka University Graduate School of Dentistry, Osaka, Japan.
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Masunaga Y, Hirahara I, Shimano Y, Kurosu M, Iimura O, Miyata Y, Amemiya M, Homma S, Kusano E, Asano Y. A case of encapsulating peritoneal sclerosis at the clinical early stage with high concentration of matrix metalloproteinase-2 in peritoneal effluent. Clin Exp Nephrol 2005; 9:85-9. [PMID: 15830280 DOI: 10.1007/s10157-004-0328-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2004] [Accepted: 10/05/2004] [Indexed: 10/25/2022]
Abstract
In encapsulating peritoneal sclerosis (EPS), matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases are involved in the remodeling of peritoneal tissue. We measured the MMP-2 concentration in the peritoneal effluents of a patient with EPS who discontinued continuous ambulatory peritoneal dialysis (CAPD) therapy because of ultrafiltration failure and/or underdialysis. First, we report a 58-year-old female patient who discontinued CAPD therapy because of underdialysis. Several months after cessation of CAPD, she complained of slightly blood-colored ascites and had an elevated level of C-reactive protein (CRP) in plasma. She was diagnosed as having clinical early-stage EPS. Peritoneal effluents drained from this case, and from 11 patients who discontinued CAPD therapy because of ultrafiltration failure and/or underdialysis, and who underwent peritoneal lavage with 1.5% dextrose peritoneal dialysis fluid for several months, were analyzed by gelatin zymography. MMP-2 concentration was also measured by enzyme-linked immunosorbent assay (ELISA). MMP-2 concentration in peritoneal effluent of this patient was highest compared with that of the other patients. There was some tendency of a positive correlation between MMP-2 concentration per 1 g protein and D/Pcr, and was negative correlation between MMP-2 concentration per 1 g of protein and D/D0 glucose. We concluded that MMP-2 is involved in the peritoneal remodeling of long-term CAPD therapy and the progression of EPS.
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Affiliation(s)
- Yoshinori Masunaga
- Division of Nephrology, Department of Internal Medicine, Jichi Medical School, 3311-1 Yakushiji, Minamikawachi-machi, Kawachi-gun, Tochigi 329-0498, Japan.
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13
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Amemiya M, Mori H, Imamura S, Toyoda A, Funayama I, Asano Y, Kusano E, Tabei K. Stimulation of NHE3 in OKP Cells by an Autocrine Mechanism. ACTA ACUST UNITED AC 2004; 96:e23-30. [PMID: 14752245 DOI: 10.1159/000075573] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2002] [Accepted: 09/22/2003] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS Chronic hypokalemia increases NHE3 activity in OKP cells. The aim of the present study was to determine whether an autocrine mechanism is involved in this activation. METHODS After incubation of OKP cells in normal-K(+) and low-K(+) media for 24 h, the potassium concentration in the low-K(+) media was adjusted to a normal level. These conditioned media were then used as the normal-K(+) and low-K(+) supernatants. Other OKP cells were incubated in these normal-K(+) and low-K(+) supernatants and the mechanism of Na(+)/H(+) antiporter activation was examined. RESULTS The EIPA-resistant Na(+)/H(+) antiporter activity of OKP cells increased after 4 h incubation in the low-K(+) supernatant, and the amount of NHE3 protein increased at 24 h. Since both BQ788 and saralasin blocked this antiporter activation, the supernatant concentration of endothelin I (ET-I) and angiotensin II (Ang-II) were measured. The ET-I concentration was reduced, but the Ang-II concentration remained unchanged. There was a significant association between a reduction in the ET-I concentration and an increase in Na(+)/H(+) antiporter activity, but only when Ang-II was present in the supernatant. CONCLUSION An autocrine mechanism is involved in the activation of NHE3 in OKP cells. Both ET-I and Ang-II play a role in this activation.
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Affiliation(s)
- Morimasa Amemiya
- Department of Internal Medicine, Division of Nephrology, Jichi Omiya Medical Center, Jichi Medical School, Saitama-shi, Saitama-Ken, Japan.
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Iimura O, Kusano E, Tanba K, Yanagiba S, Amemiya M, Ando Y, Honma S, Muto S, Asano Y. [Additive antiproteinuric effect of angiotensin II receptor antagonist and angiotensin-converting enzyme inhibitor in patients with chronic glomerulonephritis]. Nihon Jinzo Gakkai Shi 2003; 45:439-44. [PMID: 14509219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
Angiotensin II type-1 receptor blocker (ARB) and angiotensin-converting enzyme inhibitor (ACEI) have been thought to be effective for reducing proteinuria in patients with chronic glomerulonephritis. Recently, an additive effect of these two types of angiotensin blockers has been reported in patients with IgA nephropathy, but the mechanism responsible for the effect has not yet been determined. In this study, we examined additive effect of these two drugs in chronic glomerulonephritis patients. Ten patients with biopsy-proven primary glomerulonephritis (eight IgA nephropathy patients, two membranous nephropathy patients), non-nephrotic proteinuria (protein, 0.5 to 3.5 g/day) received candesartan cilexetil (2 or 4 mg) for 8 weeks. After the 8 weeks, a combination of perindopril erbumine (1 or 2 mg) and candesartan cilexetil was administered to the patients. Perindopril was stopped after the 8-week administration of the two drugs. Candesartan alone reduced proteinuria by 13%. Combination of these two drugs induced a more remarkable reduction of proteinuria (48%; p < 0.05 vs other periods). The decrease in mean blood pressure by the combination therapy was significantly correlated with the decrease in proteinuria. The combination of drugs also reduced the amount of urinary type-IV collagen excretion. An additive effect of ACEI and ARB on proteinuria and urinary type-IV collagen excretion was recognized in patients with chronic glomerulonephritis.
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Affiliation(s)
- Osamu Iimura
- Division of Nephrology, Department of Internal Medicine, Jichi Medical University, Tochigi, Japan
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Inoue M, Kusano E, Ito C, Akimoto T, Iimura O, Nemoto J, Amemiya M, Muto S, Asano Y. The anti-platelet agent, ticlopidine, upregulates interleukin-1-Beta-stimulated nitric oxide production in cultured rat vascular smooth muscle cells. Exp Nephrol 2003; 10:267-74. [PMID: 12097830 DOI: 10.1159/000063701] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Hemodialysis patients who had been treated with anti-platelet aggregation drugs, including ticlopidine, sometimes developed hypotension. The mechanism by which ticlopidine lowers the blood pressure in hemodialysis patients is unclear. To elucidate the mechanism of the action of this drug, we investigated cytokine-stimulated nitric oxide (NO) metabolism by ticlopidine in cultured rat vascular smooth muscle cells (VSMC). METHODS Nitrite, a stable metabolite of NO, and intracellular cAMP and cGMP contents were assayed by the Griess method and enzyme immunoassay, respectively. iNOS mRNA and protein expressions were analyzed by Northern blotting and Western blotting. RESULTS Ticlopidine enhanced interleukin-1beta (IL-1beta)-induced nitrite production in a dose- and time-dependent manner. The mRNA and protein expressions of inducible NO synthase were upregulated by ticlopidine in a dose- and time-dependent manner. IL-1beta alone stimulated both intracellular cAMP and cGMP contents, and the addition of ticlopidine further enhanced their contents. KT 5720, a selective inhibitor of protein kinase A, but not KT 5823, a selective inhibitor of protein kinase G, abolished the enhancement of IL-1beta-induced nitrite production by ticlopidine. In addition, a phosphodiesterase inhibitor, isobutylmethylxanthine, enhanced IL-1beta and ticlopidine induced nitrite production. CONCLUSION We concluded that ticlopidine enhanced the IL-1beta-induced NO production via cAMP and subsequent activation of protein kinase A in cultured rat VSMC.
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Affiliation(s)
- Makoto Inoue
- Division of Nephrology, Department of Medicine, Jichi Medical School, Tochigi, Japan
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Eizawa T, Murakami Y, Matsui K, Takahashi M, Muroi K, Amemiya M, Takano R, Kusano E, Shimada K, Ikeda U. Circulating endothelial progenitor cells are reduced in hemodialysis patients. Curr Med Res Opin 2003; 19:627-33. [PMID: 14606986 DOI: 10.1185/030079903125002379] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE The risk of cardiovascular disease in hemodialysis patients is far greater than in the general population. Endothelial progenitor cells (EPCs) circulating in the peripheral blood contribute to neovascularization in the ischemic tissue. EPCs are considered to be included in CD34 positive (CD34+) or AC133 positive (AC133+) mononuclear cells (MNCs). This study's aim was to determine the number and functional activity of EPCs in hemodialysis patients and age-matched control subjects. METHODS The numbers of CD34+ MNCs and AC133+ MNCs in the peripheral blood were quantified by flow cytometry. The peripheral blood EPCs were also examined by an in vitro culture assay. The levels of serum vascular endothelial growth factor (VEGF) were measured by sandwich enzyme immunoassay. RESULTS The numbers of CD34+ MNCs and AC133+ MNCs were significantly reduced by 56% and 49%, respectively, in hemodialysis patients (n = 50) compared with control subjects (n = 36). The number of EPCs determined by the culture assay was also significantly reduced by 41% in hemodialysis patients compared with control subjects. Multivariate analysis revealed that none of the atherosclerotic risk factors were independent predictors of reduced CD34+ MNC counts. The serum VEGF levels in hemodialysis patients were not different from those in control subjects and did not correlate with CD34+ MNC counts. CONCLUSION Circulating EPCs are significantly reduced in hemodialysis patients, which might be related to impaired neovascularization and cardiovascular disease in these patients.
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Affiliation(s)
- Takayuki Eizawa
- Division of Cardiovascular Medicine, Jichi Medical School, Tochigi, Japan
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Kusano E, Iimura O, Ishida F, Akimoto T, Amemiya M, Ando Y, Asano Y. Chronic hyperosmolality enhances ANP-dependent cGMP production via stimulation of transcription and protein synthesis in cultured rat IMCD cells. TOHOKU J EXP MED 2002; 197:209-20. [PMID: 12434996 DOI: 10.1620/tjem.197.209] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Recently, we found that hyperosmolality acutely inhibited atrial natriuretic peptide (ANP) dependent cGMP production by reducing ANP binding sites in cultured rat inner medullary collecting duct (IMCD) cells. Therefore, the present study was undertaken to evaluate the chronic effect of hyperosmolality on ANP dependent cGMPproduction in IMCD cells. Cell culture was carried out either in an iso-osmotic or hyperosmotic solution consisting of equi-isomolar NaCl and/or urea. Incubations with ANP and/or other agents were performed under the same osmotic conditions. ANP or SNP stimulated cGMP production was enhanced in a chronically hyperosmotic medium. These changes occurred in an osmolality-dependent manner. Hyperosmolality with sodium alone or with sodium and urea, but not with urea alone, was effective for the enhancement of ANP action. There was no significant difference between 125I-ANP specific bindings under iso-osmotic and hyperosmotic conditions. Incubation with cytoskeleton modulators did not affect ANP-dependent cGMP production stimulated by hyperosmolality. On the other hand, both actinomycin D, an inhibitor of transcription, and cycloheximide, an inhibitor of protein synthesis, prevented the stimulatory effects of hyperosmolality. The results suggest that chronic hyperosmolality enhances ANP-dependent cGMP production via stimulation of transcription and protein synthesis in cultured rat IMCD cells.
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Affiliation(s)
- Eiji Kusano
- Department of Nephrology, Jichi Medical School, Minamikawachi, Tochigi, Japan.
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Amemiya M, Kusano E, Muto S, Tabei K, Ando Y, Alpern RJ, Asano Y. Glucagon acutely inhibits but chronically activates Na(+)/H(+) antiporter 3 activity in OKP cells. Exp Nephrol 2002; 10:26-33. [PMID: 11803202 DOI: 10.1159/000049895] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND We previously found that the Na(+)/H(+) exchanger 3 (NHE3) is localized in the apical membrane of the rat renal proximal tubule and thick ascending limb of Henle. In the present study, we examined the direct effect of glucagon on the opossum kidney P (OKP) cell Na(+)/H(+) antiporter, encoded by NHE3. METHODS Na(+)/H(+) antiporter activity was measured as the rate of cell pH recovery from an acid load using 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein. Northern blot and Western blot analyses were performed using OKP NHE3 cDNA and anti-OKP-NHE3 antibodies. RESULTS Glucagon (1 ng/ml) acutely (1 h) inhibited, but chronically (24 h) activated NHE3 activity in OKP cells. These effects were blocked by either KT5720 or RpcAMP [protein kinase A (PKA) inhibitors], and mimicked by 10(-4) M dibutyryl-cAMP. Both NHE3 mRNA and protein abundance increased with the 24-hour incubation in glucagon or dibutyryl-cAMP. Cycloheximide did not prevent a significant increase in NHE3 activity at 24 h. We therefore examined NHE3 protein abundance in the surface membrane by the biotinylation method. cAMP or glucagon significantly increased NHE3 protein abundance in the surface membrane when incubated with cycloheximide for 24 h. CONCLUSIONS Glucagon acutely inhibits but chronically activates NHE3 activity in OKP cells via a PKA-dependent pathway. Both protein-synthesis-dependent and -independent mechanisms play important roles in the chronic activation of NHE3.
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Affiliation(s)
- Morimasa Amemiya
- Department of Internal Medicine, Division of Nephrology, Jichi Medical School, Tochigi, Japan.
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19
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Akimoto T, Kusano E, Ito C, Yanagiba S, Inoue M, Amemiya M, Ando Y, Asano Y. Involvement of erythropoietin-induced cytosolic free calcium mobilization in activation of mitogen-activated protein kinase and DNA synthesis in vascular smooth muscle cells. J Hypertens 2001; 19:193-202. [PMID: 11212961 DOI: 10.1097/00004872-200102000-00005] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND/OBJECTIVE Human recombinant erythropoietin (rHuEPO) induces cytosolic free calcium ([Ca2+]i) mobilization, an activation of mitogen-activated protein (MAP) kinase and DNA synthesis in several tissues. We explored the mechanism of rHuEPO-induced [Ca2+]i mobilization and its role in the activation of MAP kinase and DNA synthesis in vascular smooth muscle cells (VSMC). METHODS [Ca2+]i concentrations were measured by fura-2. MAP kinase activation was analyzed using an immunocomplex kinase assay and Western blotting. DNA synthesis was measured as an incorporation of 5-bromo-2'-deoxyuridine. RESULTS Although addition of rHuEPO significantly increased [Ca2+]i, either in the presence or absence of extracellular Ca2+, the peak level and sustained elevation of [Ca2+]i were significantly reduced in the absence of extracellular Ca2+. Pretreatment with genistein completely blocked the elevation of [Ca2+]i in both conditions. Calphostin C and staurosporine did not completely block the elevation of [Ca2+]i. Staurosporine reduced its peak level in a dose-dependent manner, whereas calphostin C reduced its peak level at concentrations over 1 nmol/l in the presence of extracellular Ca2+. Similar results to those with staurosporine were observed with nifedipine. In the absence of extracellular Ca2+, their dose-dependent effects disappeared even though rHuEPO increased [Ca2+]i. rHuEPO activated MAP kinase and DNA synthesis, both of which were significantly suppressed by the chelation of intracellular Ca2+. CONCLUSION These findings suggest that rHuEPO increases [Ca2+]i by both Ca2+ influx and Ca2+ release from intracellular stores. Tyrosine phosphorylation is critical in the regulation of [Ca2+]i, but protein kinase C activation is important only in the regulation of Ca2+ influx. Dihydropyridine-sensitive L-type Ca2+ channels seem to be involved in rHuEPO-induced Ca2+ influx. In addition, increase of [Ca2+]i by rHuEPO stimulates MAP kinase activation and DNA synthesis in VSMC.
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Affiliation(s)
- T Akimoto
- Department of Nephrology, Jichi Medical School, Minamikawachi, Tochigi, Japan
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20
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Peng Y, Amemiya M, Yang X, Fan L, Moe OW, Yin H, Preisig PA, Yanagisawa M, Alpern RJ. ET(B) receptor activation causes exocytic insertion of NHE3 in OKP cells. Am J Physiol Renal Physiol 2001; 280:F34-42. [PMID: 11133512 DOI: 10.1152/ajprenal.2001.280.1.f34] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Endothelin-1 (ET-1) activates sodium/hydrogen exchanger 3 (NHE3) in opossum kidney clone P (OKP) cells expressing ET(B) receptors. ET-1 (10(-8) M) caused a two- to threefold increase in apical membrane NHE3 (assessed by surface biotinylation), in the absence of a change in total cellular NHE3. A maximal effect was achieved within 15 min. The increase in apical NHE3 was not blocked by cytochalasin D but was blocked by latrunculin B, which also prevented the ET-1-induced increase in NHE3 activity. Endocytic internalization of NHE3, measured as protection of biotinylated NHE3 from the membrane-impermeant, sulfhydryl-reducing agent MesNa was minimal within 35 min and was not regulated by ET-1. Exocytic insertion of NHE3, measured as the appearance of biotinylated NHE3 after the blockade of reactive sites with sulfo-NHS-acetate, was increased in response to ET-1. These studies demonstrate that ET-1 induces net trafficking of NHE3 to the apical membrane that is mediated by enhanced exocytic insertion and is required for increased NHE3 activity.
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Affiliation(s)
- Y Peng
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas 75235, USA
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21
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Sueki H, Amemiya M, Watanabe H, Akiyama M, Sato S, Iijima M. Spontaneous resolution in a case of pseudo-pseudoxanthoma elasticum. Br J Dermatol 2001; 144:213-5. [PMID: 11167726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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22
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23
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Iijima M, Someno T, Amemiya M, Ishizuka M, Naganawa H, Takeuchi T. Biosynthesis of IC202C, a new siderophore with immunosuppressive activity. J Antibiot (Tokyo) 2000; 53:1411-5. [PMID: 11217808 DOI: 10.7164/antibiotics.53.1411] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- M Iijima
- Institute for Chemotherapy, MCRF, Numazu-shi, Shizuoka, Japan
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24
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Abstract
Incubation of opossum kidney clone P (OKP) cells in acid media (pH 6. 8) causes activation of Na(+)/H(+) exchanger 3 (NHE3) at 6, 12, and 24 h. OKP cell NHE3 protein abundance was increased by 45% at 24 h of acid incubation but was unaffected at 3-12 h. By contrast, apical membrane NHE3, measured by surface biotinylation, increased approximately twofold at 6, 12, and 24 h, mirroring the increase in activity. Acid incubation caused a 76% increase in exocytic insertion of NHE3 into the apical membrane but had no effect on endocytic internalization at 6 h. Latrunculin B, an inhibitor of microfilament organization, inhibited the acid-induced increases in apical membrane NHE3, exocytic insertion of NHE3, and NHE3 activity at 6 h. These studies demonstrate two mechanisms for acid-induced increases in NHE3 activity. Beginning at 6 h, there is an increase in apical membrane NHE3 that is due to stimulated exocytic insertion and is required for increased NHE3 activity. At 24 h, there is an additional increase in total cellular NHE3.
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Affiliation(s)
- X Yang
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas 75235, USA
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25
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Kawada M, Amemiya M, Ishizuka M, Takeuchi T. Cytostatin, an inhibitor of cell adhesion to extracellular matrix, selectively inhibits protein phosphatase 2A. Biochim Biophys Acta 1999; 1452:209-17. [PMID: 10559474 DOI: 10.1016/s0167-4889(99)00126-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cytostatin, which is isolated from a microbial cultured broth as a low molecular weight inhibitor of cell adhesion to extracellular matrix (ECM), has anti-metastatic activity against B16 melanoma cells in vivo. In this study, we examined a target of cytostatin inhibiting cell adhesion to ECM. Cytostatin inhibited tyrosine phosphorylation of focal adhesion kinase (FAK) and paxillin upon B16 cell adhesion to fibronectin. While the amount of FAK was not affected by cytostatin, electrophoretically slow-migrating paxillin appeared. Alkaline phosphatase treatment diminished cytostatin-induced slow-migrating paxillin. Furthermore, cytostatin increased intracellular serine/threonine-phosphorylated proteins and was found to be a selective inhibitor of protein phosphatase 2A (PP2A). Cytostatin inhibited PP2A with an IC(50) of 0.09 microgram/ml in a non-competitive manner against a substrate, p-nitrophenyl phosphate, but it had no apparent effect on other protein phosphatases including PP1, PP2B and alkaline phosphatase even at 100 microgram/ml. On the contrary, dephosphocytostatin, a cytostatin analogue, without inhibitory effect on PP2A did not affect B16 cell adhesion including FAK and paxillin. These results indicate that cytostatin inhibits cell adhesion through modification of focal contact proteins such as paxillin by inhibiting a PP2A type protein serine/threonine phosphatase. This is the first report that describes a drug with anti-metastatic ability that inhibits PP2A selectively.
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Affiliation(s)
- M Kawada
- Institute for Chemotherapy, M.C.R.F., 18-24 Miyamoto, Numazu-shi, Shizuoka, Japan
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26
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Ebata S, Muto S, Okada K, Nemoto J, Amemiya M, Saito T, Asano Y. Aldosterone activates Na+/H+ exchange in vascular smooth muscle cells by nongenomic and genomic mechanisms. Kidney Int 1999; 56:1400-12. [PMID: 10504492 DOI: 10.1046/j.1523-1755.1999.00674.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND In vascular smooth muscle cells (VSMCs), Na+/H+ exchange (NHE) plays an important role in intracellular pH (pHi) regulation. Recently, nongenomic effect of aldosterone (ALDO) on NHE activity has been suggested in VSMCs. However, the nongenomic and genomic effects of ALDO on NHE and the intracellular signaling mechanisms for these effects have not fully been determined in VSMCs. METHODS The effects of short- (3 hr) and long- (24 hr) term exposure to ALDO on NHE activity were examined in cultured VSMCs from rat thoracic aortae by using single-cell pHi measurement with the pH-sensitive dye 2'7'-bis(carboxyethyl)-5(6)-carboxyfluorescein. The NHE activity was calculated from the initial rate of Na+-dependent pHi recovery after acid load. RESULTS The NHE activity significantly increased after short- and long-term exposure of VSMCs to ALDO (10(-6) M). The inhibitors of gene transcription (actinomycin D) and of protein synthesis (cycloheximide) had no effect on the short-term ALDO effect, but inhibited the long-term ALDO effect. The antagonists of the mineralocorticoid receptor (MR) (spironolactone) and of the glucocorticoid receptor (GR) (RU38486) caused no effect on the short-term ALDO effect, but inhibited the long-term ALDO effect. Two protein kinase C (PKC) inhibitors (staurosporine A and calphostin C) and PKC down-regulation (24 hr pre-exposure to phobol 12-myristate 13-acetate, PMA) inhibited both the short- and long-term ALDO effects. Exposure of VSMCs to PMA for 3 hours mimicked the short-term effect of ALDO on NHE activity. ALDO significantly increased PKC activity in VSMCs. The short-term ALDO effect was inhibited by disruptors of microtubule (colchicine) and of filamentous-actin (cytochalasin B). Long-term exposure of ALDO caused a threefold increase in NHE (NHE-1) mRNA levels. CONCLUSIONS The short-term effect of ALDO on NHE activity is not mediated through either MR or GR, occurs independent of gene transcription and protein synthesis, and occurs through a mechanism involving the structural elements of cytoskeleton. The long-term effect of ALDO on NHE activity occurs through both MR and GR and requires gene transcription and protein synthesis. Both short- and long-term effects of ALDO are mediated through PKC activation. Therefore, ALDO activates NHE by nongenomic and genomic mechanisms in VSMCs.
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MESH Headings
- Aldosterone/pharmacology
- Animals
- Aorta, Thoracic/cytology
- Cells, Cultured
- Cycloheximide/pharmacology
- Cytoskeleton/physiology
- Dactinomycin/pharmacology
- Dose-Response Relationship, Drug
- Enzyme Activation/drug effects
- Gene Expression/drug effects
- Hormone Antagonists/pharmacology
- Hydrogen-Ion Concentration/drug effects
- Male
- Mifepristone/pharmacology
- Mineralocorticoid Receptor Antagonists/pharmacology
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/enzymology
- Protein Kinase C/metabolism
- Protein Synthesis Inhibitors/pharmacology
- RNA, Messenger/analysis
- Rats
- Rats, Sprague-Dawley
- Signal Transduction/genetics
- Sodium-Hydrogen Exchangers/genetics
- Sodium-Hydrogen Exchangers/metabolism
- Spironolactone/pharmacology
- Transcription, Genetic/drug effects
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Affiliation(s)
- S Ebata
- Department of Nephrology, Jichi Medical School, Minamikawachi Tochigi, Japan
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27
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Umino T, Kusano E, Muto S, Akimoto T, Yanagiba S, Ono S, Amemiya M, Ando Y, Homma S, Ikeda U, Shimada K, Asano Y. AVP inhibits LPS- and IL-1beta-stimulated NO and cGMP via V1 receptor in cultured rat mesangial cells. Am J Physiol 1999; 276:F433-41. [PMID: 10070167 DOI: 10.1152/ajprenal.1999.276.3.f433] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present study examined how arginine vasopressin (AVP) affects nitric oxide (NO) metabolism in cultured rat glomerular mesangial cells (GMC). GMC were incubated with test agents and nitrite, and intracellular cGMP content, inducible nitric oxide synthase (iNOS) mRNA, and iNOS protein were analyzed by the Griess method, enzyme immunoassay, and Northern and Western blotting, respectively. AVP inhibited lipopolysaccharide (LPS)- and interleukin-1beta (IL-1beta)-induced nitrite production in a dose- and time-dependent manner, with concomitant changes in cGMP content, iNOS mRNA, and iNOS protein. This inhibition by AVP was reversed by V1- but not by oxytocin-receptor antagonist. Inhibition by AVP was also reproduced on LPS and interferon-gamma (IFN-gamma). Protein kinase C (PKC) inhibitors reversed AVP inhibition, whereas PKC activator inhibited nitrite production. Although dexamethasone and pyrrolidinedithiocarbamate (PDTC), inhibitors of nuclear factor-kappaB, inhibited nitrite production, further inhibition by AVP was not observed. AVP did not show further inhibition of nitrite production with actinomycin D, an inhibitor of transcription, or cycloheximide, an inhibitor of protein synthesis. In conclusion, AVP inhibits LPS- and IL-1beta-induced NO production through a V1 receptor. The inhibitory action of AVP involves both the activation of PKC and the transcription of iNOS mRNA in cultured rat GMC.
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Affiliation(s)
- T Umino
- Department of Nephrology, Jichi Medical School, Tochigi, 329-0498 Japan
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28
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Amemiya M, Tabei K, Kusano E, Asano Y, Alpern RJ. Incubation of OKP cells in low-K+ media increases NHE3 activity after early decrease in intracellular pH. Am J Physiol 1999; 276:C711-6. [PMID: 10069999 DOI: 10.1152/ajpcell.1999.276.3.c711] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Chronic hypokalemia increases the activity of proximal tubule apical membrane Na+/H+ antiporter NHE3. The present study examined the effect of the incubation of OKP cells (an opossum kidney, clone P cell line) in control medium (K+ concn ([K+]) = 5.4 mM) or low-K+ medium ([K+] = 2.7 mM) on NHE3. The activity of an ethylisopropyl amiloride-resistant Na+/H+ antiporter, whose characteristics were consistent with those of NHE3, was increased in low-K+ cells beginning at 8 h. NHE3 mRNA and NHE3 protein abundance were increased 2.2-fold and 62%, respectively, at 24 h but not at 8 h. After incubation in low-K+ medium, intracellular pH (pHi) decreased by 0.27 pH units (maximum at 27 min) and then recovered to the control level. Intracellular acidosis induced by 5 mM sodium propionate increased Na+/H+ antiporter activity at 8 and 24 h. Herbimycin A, a tyrosine kinase inhibitor, blocked low-K+- and sodium propionate-induced activation of the Na+/H+ antiporter at 8 and 24 h. Our results demonstrate that low-K+ medium causes an early decrease in pHi, which leads to an increase in NHE3 activity via a tyrosine kinase pathway.
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Affiliation(s)
- M Amemiya
- Division of Nephrology, Department of Internal Medicine, Jichi Medical School, Tochigi, Japan 329-0498, USA
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29
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Fujisato H, Amemiya M, Hayashi Y, Ogawa M, Nakano I, Ikeda H, Takahashi H, Naitou E, Funayama I, Saitou O, Ando Y, Homma S, Muto S, Asano Y. Treatment with steroids and double filtration plasmapheresis for a case of anti-GQ1b antibody-positive Bickerstaff's encephalitis. Ther Apher 1999; 3:72-4. [PMID: 10079809 DOI: 10.1046/j.1526-0968.1999.00141.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The treatment of Bickerstaff's brainstem encephalitis (BBE) is still controversial. We report a case of BBE with positive anti-GQ1b antibody. The patient was successfully treated with steroids and double filtration plasmapheresis.
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Affiliation(s)
- H Fujisato
- Department of Nephrology, Jichi Medical School, Tochigi, Japan
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30
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Abstract
Most solid tumor cells are less sensitive to apoptosis induced by anticancer drugs than hematopoietic cancer cells. However, the mechanisms of the different responses to apoptosis in these cell types remain unknown. To explore this question, we used B16 melanoma and EL-4 lymphoma cells as solid tumor- and hematopoietic cancer-derived cell lines, and examined the effects of two apoptosis inducers, cytostatin and bactobolin, on both cell lines. Apoptosis in B16 cells was induced strongly by bactobolin, but weakly by cytostatin. In contrast, apoptosis in EL-4 cells was induced strongly by cytostatin, but weakly by bactobolin. While caspase-3 was activated upon induction of apoptosis in both cell lines, Ac-DEVD-CHO, a specific inhibitor of caspase-3, suppressed only the apoptosis in B16 cells. In B16 cells, cyclins E, A, and B1 were decreased by strongly apoptosis-inducing bactobolin prior to apoptosis commitment, but cyclin E was not decreased by weakly apoptosis-inducing cytostatin. On the other hand, in EL-4 cells cyclins D1, E, A, and B1 were decreased by strongly apoptosis-inducing cytostatin prior to apoptosis commitment, but neither cyclin A nor B1 was decreased by weakly apoptosis-inducing bactobolin. These results indicate that the dependency of apoptosis induction on caspase activity is different between the two cell lines. Furthermore, there may be an inverse correlation between specific cyclins and apoptosis induction in the two cell lines.
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Affiliation(s)
- M Kawada
- Institute for Chemotherapy, M. C. R. F., Shizuoka
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31
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Iijima M, Someno T, Amemiya M, Sawa R, Naganawa H, Ishizuka M, Takeuchi T. IC202A, a new siderophore with immunosuppressive activity produced by Streptoalloteichus sp. 1454-19. II. Physico-chemical properties and structure elucidation. J Antibiot (Tokyo) 1999; 52:25-8. [PMID: 10092193 DOI: 10.7164/antibiotics.52.25] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
IC202A (1) was isolated from the culture filtrate of Streptoalloteichus sp. 1454-19. The structure of 1 was determined by spectral analysis including a variety of two-dimentional NMR and FAB-MS experiments. IC202A is a ferrioxamine-related compound containing a butylidene N-oxide function.
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Affiliation(s)
- M Iijima
- Institute for Chemotherapy, MCRF, Shizuoka, Japan
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32
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Abstract
This study investigated the effect of chronic hypertonicity on the OKP cell Na/H antiporter, encoded by Na/H exchanger 3 (NHE3). Chronic (48 h) increases in extracellular glucose, mannitol, or raffinose concentration caused a significant increase in Na/H antiporter activity, while increases in urea concentration were without effect. This effect was seen with changes in osmolality of only 20 mOsm/liter, a magnitude that is observed clinically in poorly controlled diabetes mellitus. Increases in mannitol concentration acutely inhibited and chronically stimulated Na/H antiporter activity. The increase in Na/H antiporter activity induced by hypertonic incubation was resistant to 10(-7) and 5 x 10(-6) M but inhibited by 10(-4) M ethylisopropyl amiloride, consistent with regulation of NHE3. In addition, hypertonicity increased total cellular and plasma membrane NHE3 protein abundance twofold, with only a small increase in NHE3 mRNA abundance. We conclude that chronic pathophysiologically relevant increases in tonicity lead to increases in NHE3 protein abundance and activity. This may be responsible for increased proximal tubule apical membrane Na/H antiporter activity in poorly controlled diabetes mellitus, which could then contribute to hypertension, glomerular hyperfiltration and diabetic nephropathy.
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Affiliation(s)
- P Ambühl
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas 75235-8856, USA
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33
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Abstract
Ultrasonically nebulized distilled water-induced bronchoconstriction (UNDW-IB) is specific to asthma. The mechanisms underlying UNDW-IB are not fully understood, and no reproducible animal model has been reported. The purpose of this study was to develop a guinea-pig model of UNDW-IB. Ultrasonically nebulized distilled water (UNDW) was inhaled 20 min after an aerosolized antigen challenge in passively sensitized and artificially ventilated guinea-pigs. UNDW was also inhaled 5 and 20 min after 0.1 mg x mL(-1) methacholine inhalation in nonsensitized animals. In addition, 0.1 mg x kg(-1) S-1452, a thromboxane A2 antagonist, or saline was given intravenously 5 min before UNDW inhalation in sensitized animals. The inhalation of UNDW caused bronchoconstriction, when inhaled 20 min after an antigen challenge in sensitized guinea-pigs. UNDW inhalation did not produce bronchoconstriction after saline inhalation in nonsensitized or sensitized guinea-pigs, or after antigen inhalation in nonsensitized animals. Methacholine-induced bronchoconstriction did not evoke UNDW-IB. Neither did S-1452 reduce the UNDW-IB. In conclusion, the guinea-pig model of ultrasonically nebulized distilled water-induced bronchoconstriction developed in this study suggests that allergic reaction, but not bronchoconstriction, can induce bronchial hyperresponsiveness to ultrasonically nebulized distilled water, and that thromboxane A2 is not involved in ultrasonically nebulized distilled water-induced bronchoconstriction.
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Affiliation(s)
- M Fujimura
- The Third Dept of Internal Medicine, Kanazawa University School of Medicine, Japan
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34
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Ambühl PM, Amemiya M, Danczkay M, Lötscher M, Kaissling B, Moe OW, Preisig PA, Alpern RJ. Chronic metabolic acidosis increases NHE3 protein abundance in rat kidney. Am J Physiol 1996; 271:F917-25. [PMID: 8898023 DOI: 10.1152/ajprenal.1996.271.4.f917] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Chronic metabolic acidosis increases the activity of the proximal tubule apical membrane Na/H antiporter, which is encoded predominantly by the NHE3 isoform. The present studies examined the effect of chronic metabolic acidosis on apical membrane NHE3 protein abundance in rats. Rats subjected to NH4Cl in their drinking water developed a metabolic acidosis, which decreased in magnitude over 14 days. During this time, renal cortical brush-border membrane NHE3 protein abundance, assessed by Western blot, increased progressively (28% at 3 days, 59% at 7 days, and 90% at 14 days). Immunohistochemistry revealed that the acidosis-induced increase in NHE3 abundance occurred in the apical membranes of the S1 and S2 segments of the proximal tubule and the thick ascending limb. NHE3 mRNA abundance was not significantly increased in these animals, whereas phosphoenolpyruvate carboxykinase and glyceraldehyde-3-phosphate dehydrogenase mRNA abundances were significantly increased. These studies demonstrate that the increase in Na/H antiporter activity seen in metabolic acidosis involves an increase in NHE3 protein abundance, which is distributed along the proximal tubule and the thick ascending limb. In addition, these studies suggest that a component of this adaptation is unrelated to changes in NHE3 mRNA abundance.
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Affiliation(s)
- P M Ambühl
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas 75235-8856, USA
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Iimura O, Kusano E, Amemiya M, Muto S, Ikeda U, Shimada K, Asano Y. Dipyridamole enhances interleukin-1beta-stimulated nitric oxide production by cultured rat vascular smooth muscle cells. Eur J Pharmacol 1996; 296:319-26. [PMID: 8904084 DOI: 10.1016/0014-2999(95)00712-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We examined whether dipyridamole affected interleukin-1beta-stimulated nitric oxide (NO) production by cultured rat vascular smooth muscle cells. Interleukin-1beta stimulated the production of nitrite and nitrate, stable metabolites of NO, in a dose- and time-dependent manner in vascular smooth muscle cells. Dipyridamole (1-100 mu M) enhanced interleukin-1beta-induced nitrite production in a dose- and time-dependent manner. The mRNA expression of inducible NO synthase was up-regulated by dipyridamole (0.3-10 mu M) treatment in a dose-dependent manner. Both 8-bromo-guanosine 3',5'-cyclic monophosphate (8-bromo-cGMP) and dibutyryl adenosine 3',5'-cyclic monophosphate (db-cAMP) enhanced the nitrite production in the presence of interleukin-1beta. Dipyridamole up-regulated the effect of both 8-bromo-cGMP and db-cAMP on the interleukin-1beta-induced nitrite production. Dipyridamole increased the intracellular cAMP content in the presence of interleukin-1beta (10 ng/ml), but did not affect the intracellular cGMP content. 8R*,9S*,11S*-(-)-9-hydroxy-9-n-hexyloxy-8-methyl-2,3,9,10- tetrahydro-8,11-epoxy-1H,8H,11H-2,7b,11a-triazadibenzo-(a,g)-cy cloocta ++-(c,d,e)-trinden-1-one (KT 5720), a selective inhibitor of cAMP-dependent protein kinase, abolished the enhancement of interleukin-1beta-induced nitrite production by dipyridamole, whereas 8R*,9S*,11S*-(-)-9-methoxy-carbamyl-8-methyl-2,3,9,10-tetrahydro-8,11-ep oxy-1H,8H,11H-2,7b,11a-trizadibenzo-(a,g)-cyclo-octa-(c,d,e)-tr inden-1-one (KT 5823), an inhibitor of cGMP-dependent protein kinase, did not attenuate the enhancement. Furthermore, Rolipram and 4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone (Ro-20-1724), cAMP-specific phosphodiesterase type IV inhibitors, augmented the interleukin-1beta-induced nitrite production. We concluded that dipyridamole enhanced the interleukin-1beta-induced NO production via an increase in intracellular cAMP content in cultured rat vascular smooth muscle cells.
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Affiliation(s)
- O Iimura
- Department of Nephrology, Jichi Medical School, Minamikawachi, Japan
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Akai Y, Kusano E, Amemiya M, Ono S, Takeda S, Homma S, Asano Y. PMA and ionomycin differently affect atrial natriuretic peptide stimulated cyclic GMP production in rat mesangial cells. TOHOKU J EXP MED 1996; 178:137-49. [PMID: 8727695 DOI: 10.1620/tjem.178.137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
How 4 beta-phorbol 12-myristate 13-acetate (PMA) and ionomycin (Io), a calcium ionophore, affect on the atrial natriuretic peptide (ANP) stimulated cyclic-3',5'-guanosine monophosphate (cGMP) production in cultured rat mesangial cells was examined. Cultured mesangial cells were prepared by isolated glomeruli from Sprague Dawley rats employing the sieving method and were used between the 3rd and 15th passage for experiments. cGMP and protein contents were measured by radioimmunoassay and Lowry method. Incubations with effectors were carried out either in the presence or absence of 0.5 mM 1-methyl-3-isobutyl-xanthine (MIX). The intracellular concentration of calcium ([Ca2+]i) was determined by using the Fura-2 method. Pretreatment with PMA, an activator of protein kinase C (PKC), attenuated ANP stimulated cGMP production in a time- and dose-dependent fashion, while alpha PDD (an inactive analog of PMA) did not inhibit cGMP production. PMA inhibition was reversed by addition of staurosporine, a protein kinase C inhibitor. Io attenuated ANP stimulated cGMP production in the absence but not in the presence of MIX. These findings suggested that PMA acts on ANP receptor or guanylate cyclase via activation of PKC in rat mesangial cells. Io may inhibit ANP stimulated cGMP production via activation of cyclic nucleotide phosphodiesterase.
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Affiliation(s)
- Y Akai
- Department of Medicine, Jichi Medical School, Tochigi, Japan
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37
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Abstract
OKP cells express NHE-3, an amiloride-resistant Na+/H+ antiporter, which is likely an isoform responsible for apical proton secretion by the proximal tubule. We have previously shown that an amiloride-resistant Na+/H+ antiporter in OKP cells is regulated by dexamethasone, a synthetic glucocorticoid. The purpose of the present study was to examine the mechanism for the glucocorticoid-mediated increase in Na+/H+ antiporter activity. Incubation of OKP cells with 10(-6) M dexamethasone resulted in a two- to threefold increase in NHE-3 mRNA abundance. This increase was seen after 4 h of incubation with dexamethasone, a time course similar to that found for Na+/H+ antiporter activity. To examine the mechanism for the increase in NHE-3 mRNA abundance, mRNA half-life and in vitro transcription experiments were performed. NHE-3 mRNA had a half-life of 8 h in control and dexamethasone-treated cells. The rate of in vitro transcription was 1.8-fold greater when OKP cells were treated with dexamethasone. These data suggest that the glucocorticoid-mediated increase in Na+/H+ antiporter activity is due to an increase in NHE-3 gene transcription.
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Affiliation(s)
- M Baum
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, USA
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38
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Abstract
In the mammalian renal proximal tubule, protein kinase A (PKA) plays an important role in mediating hormonal regulation of apical membrane Na/H exchanger activity. This exchanger is likely encoded by NHE-3. The present studies examined regulation of NHE-3 by PKA. NHE-3 was stably expressed in Na/H exchanger-deficient fibroblasts (AP-1/NHE-3 cells). PKA activation (0.1 mM 8-BrcAMP x 20 min) inhibited NHE-3 activity by 39% (P < 0.01) with no change in NHE-3 protein abundance in the plasma membrane. To define the structural requirements for PKA-mediated inhibition, full-length NHE-3 and a cytoplasmic domain-truncated mutant (NHE-3 delta cyto) were expressed in Xenopus laevis oocytes. 8-BrcAMP inhibited NHE-3 activity by 27% (P < 0.05), an effect that was blocked by 10(-7) M PKA inhibitor peptide. NHE-3 delta cyto had baseline activity similar to that of full-length NHE-3 but its activity was not regulated by 8-BrcAMP. The purified recombinant cytoplasmic domain of NHE-3 was phosphorylated in vitro by the catalytic subunit of PKA on serine residues. In AP-1/NHE-3 cells, NHE-3 was immunoprecipitated as a approximately 87-kD phosphoprotein. Addition of 0.1 mM 8-BrcAMP increased the phosphocontent of NHE-3 by threefold. In summary, acute activation of PKA inhibits NHE-3 activity, an effect that is likely mediated by phosphorylation of its cytoplasmic domain.
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Affiliation(s)
- O W Moe
- Department of Internal Medicine, Department of Veterans Affairs, Dallas, Texas, USA
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39
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Yamazaki K, Amemiya M, Ishizuka M, Takeuchi T. Screening for apoptosis inducers in microbial products and induction of apoptosis by cytostatin. J Antibiot (Tokyo) 1995; 48:1138-40. [PMID: 7490221 DOI: 10.7164/antibiotics.48.1138] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We have employed the DNA-methylgreen binding assay as a primary screening method for identifying apoptosis inducers in microbial products. Capsimycin, toyocamycin and cytostatin affect the binding of methylgreen to DNA of FS3 cells in this test system. The effect of cytostatin on apoptosis induction was confirmed by means of the ELISA system.
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Affiliation(s)
- K Yamazaki
- Institute for Chemotherapy, M. C. R. F., Shizuoka, Japan
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40
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Amemiya M, Loffing J, Lötscher M, Kaissling B, Alpern RJ, Moe OW. Expression of NHE-3 in the apical membrane of rat renal proximal tubule and thick ascending limb. Kidney Int 1995; 48:1206-15. [PMID: 8569082 DOI: 10.1038/ki.1995.404] [Citation(s) in RCA: 284] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Apical membrane Na/H exchange is a principal mechanism of renal proximal tubule Na absorption and H secretion, and thick ascending limb H secretion. Based on current data on Na/H exchanger isoforms (NHE-1 to 5), NHE-3 is the likeliest candidate for the apical membrane isoform. The present study localizes NHE-3 in rat kidney using polyclonal antisera against cytoplasmic epitopes of rat NHE-3. These antisera recognized an approximately 87 kD protein in Na/H exchanger-deficient cells transfected with the rat NHE-3 gene but not in mock-transfected cells. All antisera labeled an approximately 87 kD protein in plasma membranes from cortex and outer medulla. Fractionation of cortical membranes showed labeling in apical but not basolateral membranes. Cross linking studies suggested existence of oligomeric forms of the transporter. Immunohistochemistry showed strong staining of the apical membrane of S1 convoluted, and S2 convoluted tubule with lesser staining of the S2 straight tubule and absent staining of S3. Weak staining was observed in thin descending limbs in the inner stripe and intense staining was seen in the apical membrane of medullary and cortical thick ascending limbs. NHE-3 staining was absent in the remainder of the nephron. In summary, NHE-3 is the isoform responsible for NaCl and NaHCO3 absorption in the proximal convoluted tubule, and NaHCO absorption in the thick ascending limb. In the S3 proximal tubule and the distal convoluted tubule, apical membrane Na/H exchange activity is likely mediated by other isoform(s) of the NHE family.
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Affiliation(s)
- M Amemiya
- Department of Internal Medicine, Department of Veterans Affairs Medical Center, Dallas, Texas, USA
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41
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Yamaji Y, Amemiya M, Cano A, Preisig PA, Miller RT, Moe OW, Alpern RJ. Overexpression of csk inhibits acid-induced activation of NHE-3. Proc Natl Acad Sci U S A 1995; 92:6274-8. [PMID: 7541536 PMCID: PMC41500 DOI: 10.1073/pnas.92.14.6274] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Opossum kidney OKP cells express an apical membrane Na+/H+ antiporter that is encoded by NHE-3 (for Na+/H+ exchanger 3) and is similar in many respects to the renal proximal tubule apical membrane Na+/H+ antiporter. Chronic incubation of OKP cells in acid medium for 24 hr increases Na+/H(+)-antiporter activity and NHE-3 mRNA abundance. The increase in Na+/H(+)-antiporter activity was not prevented by H7, a protein kinase C/protein kinase A inhibitor, but was prevented by herbimycin A, a tyrosine kinase inhibitor. Incubation of cells in acid medium increased c-src activity, and this was inhibited by herbimycin A. To determine the role of the src family of nonreceptor protein-tyrosine kinases, Csk (for carboxyl-terminal src kinase), a physiologic inhibitor of these kinases, was overexpressed in OKP cells. In three clones overexpressing csk, acid-induced increases in Na+/H(+)-antiporter activity and NHE-3 mRNA abundance were inhibited. In these clones, inhibition of acid activation of Na+/H(+)-antiporter activity paralleled inhibition of acid activation of c-src. Neither herbimycin A nor overexpression of csk inhibited dexamethasone-induced increases in Na+/H(+)-antiporter activity. These studies show that decreases in pH activate c-src and that the src family nonreceptor protein-tyrosine kinases play a key role in acid activation of NHE-3.
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Affiliation(s)
- Y Yamaji
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas 75235-8856, USA
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42
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Abstract
With the use of degenerate primers based on conserved amino acid sequences in human, rat, and rabbit Na/H exchanger-3 (NHE-3), a polymerase chain reaction product was obtained from reverse-transcribed OKP (a clonal opossum kidney cell line) mRNA and used to screen an OKP cDNA library. The clone obtained predicted an amino acid sequence that was 86% identical to rat NHE-3, 33% to NHE-1, 35% to NHE-2, and 30% to NHE-4. Expression of the corresponding cRNA in Xenopus oocytes induced 22Na uptake with ethylisopropylamiloride. (EIPA) resistance similar to that of the OKP Na/H antiporter. On RNA blot, the cDNA labeled a 9.5-kb transcript whose abundance was increased 2.2-fold by 24-h incubation of OKP cells at pH 7.0 and 2.5-fold by 24-h incubation at pH 6.8. The acid-induced increase in NHE-3 mRNA was detectable at 12 h and increased further at 24 h. Incubation in acid media caused an increase in EIPA-resistant Na/H antiporter activity that preceded the increase in NHE-3 mRNA. In summary, OKP cells express an NHE-3 transcript that encodes an EIPA-resistant Na/H antiporter and is chronically regulated by acid.
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Affiliation(s)
- M Amemiya
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas 75235-8856, USA
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43
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Masuda T, Watanabe S, Amemiya M, Ishizuka M, Takeuchi T. Inhibitory effect of cytostatin on spontaneous lung metastases of B16-BL6 melanoma cells. J Antibiot (Tokyo) 1995; 48:528-9. [PMID: 7622443 DOI: 10.7164/antibiotics.48.528] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- T Masuda
- Institute for Chemotherapy, M.C.R.F., Shizuoka, Japan
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44
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Kasahara T, Sakurai Y, Amemiya M, Oguchi K, Hisamitsu T. Suppressive effects of central opioids on delayed type hypersensitivity to trinitrochlorobenzene: comparative study with morphine and electroacupuncture. In Vivo 1995; 9:177-81. [PMID: 8562877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We reported previously that electroacupuncture (Acu) applied to the acu-point equivalent to GV4 in the mouse just before the 2,4,6-trinitrochlorobenzene (TNCB) challenge suppressed the delayed type hypersensitivity (DTH) through endogenous opioidergic systems in the brain, and the pituitary was pivotal in this immunosuppression. The purpose of the present study was to compare the suppressive effects of Acu with those of single, acute doses of morphine on TNCB-DTH in intact and hypophysectomized (HPX) mice. Subcutaneous morphine 10 mg/kg in ddY mice, 30 mg/kg in BALB/c mice or intracisternal morphine 40 micrograms/mouse in BALB/c mice given just before TNCB challenge suppressed (40-53%) the maximal extent of ear swelling at 24 hrs after challenge in intact mice. In HPX mice, the suppressive effects of intracisternal morphine 10 and 100 micrograms/mouse were less pronounced than those observed in intact mice and there was no significant difference between intact and HPX groups. In addition, suppressive effects observed with Acu or subcutaneous morphine (30 mg/kg) were effectively antagonized by pretreatment with intracisternal naloxone at a dose of as low as 2 micrograms/mouse. Naloxone alone had no effect of its own. These results suggest that 1) the activation of opioid receptor-mediated pathways in the brain, which occurs when opioids are endogenously released (Acu) or exogenously given (morphine), is important in the suppression of TNCB-induced DTH, a cell-mediated immune response, and 2) the pituitary is less pivotal in the suppressive effects of acute morphine than in those of Acu.
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Affiliation(s)
- T Kasahara
- Department of Physiology, School of Medicine, Showa University, Tokyo, Japan
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45
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Alpern RJ, Yamaji Y, Amemiya M, Cano A, Preisig PA, Miller RT, Moe OW. Renal Proximal Tubule Response to Acid. Physiology (Bethesda) 1995. [DOI: 10.1152/physiologyonline.1995.10.2.77] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Changes in dietary acid and blood pH lead to adaptations in key enzymes and transport proteins of the renal proximal tubule that tend to return blood pH to normal. The mechanisms responsible, as well as acid-regulated signaling pathways that may effect these responses, are reviewed.
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46
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Amemiya M, Someno T, Sawa R, Naganawa H, Ishizuka M, Takeuchi T. Cytostatin, a novel inhibitor of cell adhesion to components of extracellular matrix produced by Streptomyces sp. MJ654-NF4. II. Physico-chemical properties and structure determination. J Antibiot (Tokyo) 1994; 47:541-4. [PMID: 8040051 DOI: 10.7164/antibiotics.47.541] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The structure of cytostatin was determined to be 5,6-dihydro-5-methyl-6-(6-hydroxy,1,5-dimethyl-4-phosphonooxy-7,9, 11-tridecatrienyl)-2H-pyran-2-one sodium salt on the basis of physico-chemical properties and NMR studies.
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Affiliation(s)
- M Amemiya
- Institute for Chemotherapy, M.C.R.F. Shizuoka, Japan
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47
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Amemiya M, Ueno M, Osono M, Masuda T, Kinoshita N, Nishida C, Hamada M, Ishizuka M, Takeuchi T. Cytostatin, a novel inhibitor of cell adhesion to components of extracellular matrix produced by Streptomyces sp. MJ654-NF4. I. Taxonomy, fermentation, isolation and biological activities. J Antibiot (Tokyo) 1994; 47:536-40. [PMID: 8040050 DOI: 10.7164/antibiotics.47.536] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Cytostatin has been identified as a novel inhibitor of cell adhesion to components of extracellular matrix (ECM) in cultured broth of Streptomyces sp. MJ654-NF4. Though cytostatin did not inhibit EL-4 cell adhesion to ECM components such as laminin and fibronectin; it inhibited the adhesion of B16 melanoma cells to laminin and collagen type IV but not to fibronectin. It exhibited antimetastatic activity on B16 melanoma cells in mice. The cytotoxicity of cytostatin are also reported.
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Affiliation(s)
- M Amemiya
- Institute for Chemotherapy, M. C. R. F. Shizuoka, Japan
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48
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Abstract
The biosynthesis of antitumor antibiotic cytogenin, 3-hydroxymethyl-6-methoxy-8-hydroxy-isocoumarin, was studied by feeding 14C- or 13C-labeled compounds to culture of the producing organism, Streptoverticillium eurocidicum MI43-37F11. 14C-Acetate and 14C-methionine were efficiently incorporated into cytogenin as precursors. 13C NMR studies proved that the carbon skeleton of cytogenin is derived from pentaketide intermediate due to head-to-tail condensation of five acetate units and methyl group of 6-OCH3 is derived from methionine. It was suggested that 3-hydroxymethyl and/or 6-methoxy group of cytogenin were metabolized by hydroxylation and/or methylation from three intermediates.
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Affiliation(s)
- H Kumagai
- Institute for Chemotherapy, M.C.R.F., Shizuoka, Japan
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49
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Ueno M, Amemiya M, Someno T, Masuda T, Iinuma H, Naganawa H, Hamada M, Ishizuka M, Takeuchi T. IC101, extracellular matrix antagonist produced by Streptomyces sp. MJ202-72F3. Production, isolation, structure determination and biological activity. J Antibiot (Tokyo) 1993; 46:1658-65. [PMID: 8270487 DOI: 10.7164/antibiotics.46.1658] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In our search for inhibitors of cell adhesion to components of extracellular matrix (ECM), fibronectin, laminin and collagen type IV, we succeeded in finding a novel cyclic hexadepsipeptide antibiotic, named IC101, which was isolated from cultured mycelium of Streptomyces albulus MJ202-72F3. It was purified by centrifugal partition chromatography, preparative reverse phase HPLC and Sephadex LH-20 and was obtained as a white powder. IC101 strongly inhibited cell adhesion to ECM components, suppressed immune responses in vitro and in vivo, and exhibited antimicrobial activity on Gram-positive bacteria.
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Affiliation(s)
- M Ueno
- Institute for Chemotherapy, Microbial Chemistry Research Foundation, Shizuoka, Japan
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50
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Ueno M, Yoshinaga I, Amemiya M, Someno T, Iinuma H, Ishizuaka M, Takeuchi T. Delaminomycins, novel extracellular matrix receptor antagonists. V. Biosynthesis. J Antibiot (Tokyo) 1993; 46:1390-6. [PMID: 8226318 DOI: 10.7164/antibiotics.46.1390] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The biosynthesis of delaminomycin A, produced by Streptomyces albulus MJ202-72F3, was investigated by feeding 13C-labeled compounds followed by 13C NMR analyses. The results indicate that delaminomycin A is derived from six acetate units, five propionate units and one glycine unit.
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Affiliation(s)
- M Ueno
- Institute for Chemotherapy, Microbial Chemistry Research Foundation, Shizuoka, Japan
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