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Dardik A, Yamashita A, Aziz F, Paszkowiak J, Asada H, Sumpio B. Shear stress stimulated endothelial cell derived PDGF and IL-1 alpha both stimulate SMC chemotaxis via the MAPK pathway. J Surg Res 2003. [DOI: 10.1016/j.jss.2003.08.159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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77
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Yamashita A, Norton EB, Williamson RT, Ho DM, Sinishtaj S, Mansour TS. Use of bis-(chiral alpha-methylbenzyl)glycine esters for synthesis of enantiopure beta-hydroxyamino esters. Org Lett 2003; 5:3305-8. [PMID: 12943413 DOI: 10.1021/ol030085j] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[reaction: see text] Aldol reactions using bis-(chiral alpha-methylbenzyl)glycine esters with aldehydes gave excellent diastereoselectivity. Thus, an enantiopure ribosylglycine was prepared for the synthesis of analogues of the natural antibiotics muraymycin. This method was extended for formation of beta-hydroxyamino esters.
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78
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Yamashita A, Marutsuka K, Furukoji E, Tamura S, Asada Y. Combination of increased vascular thrombogenesity and blood flow alteration promote obstructive thrombus formation in rabbit femoral artery. J Thromb Haemost 2003. [DOI: 10.1111/j.1538-7836.2003.tb04509.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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79
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Higuchi M, Hirata K, Yamashita A, Nishi K. Effects of epinephrine on underperfusion-reperfusion injuries in diabetic and non-diabetic rat hearts. Mol Cell Biochem 2003; 248:157-63. [PMID: 12870668 DOI: 10.1023/a:1024144520596] [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: 11/12/2022]
Abstract
The sympathetic nervous systems may bear relevance to the increased incidence of heart failure in diabetes (DM). In our isolated rat hearts perfused at constant low flow rate, norepinephrine dose-dependently enhanced diabetic myocardial damage, particularly during underperfusion. The purpose of this investigation is to examine the effects of epinephrine on the ischemic injury and on the reperfusion injury in DM and non-DM rat hearts, and to clarify whether the cardiac states during underperfusion at constant low pressure are similar to those at constant low flow rate. Isolated streptozotocin-induced 6-week DM and non-DM rat hearts with a balloon in the left ventricle (LV) were paced and normal perfused at 75 cm H2O with normoxic Krebs-Henseleit solution. Then the hearts were underperfused at 35 cm H2O, a constant low pressure with below one-third of the pre-ischemic coronary perfusion flow (CPF) level. Four min after the start of underperfusion, the perfusate was changed to that containing epinephrine 10(-6) M. After 45 min underperfusion with or without epinephrine, all of the hearts were reperfused without epinephrine at 75 cm H2O for 45 min. To detect changes in LV stiffness, the isometric tension along the longitudinal direction of the whole heart and the LV isovolumic pressure were monitored simultaneously. In DM hearts, the underperfusion alone caused a slight increase in LV stiffness, and all the changes recovered to the pre-ischemic levels during reperfusion. Epinephrine during underperfusion accelerated the start of increase in LV stiffness and the decrease in CPF. During reperfusion the changes recovered partly to the control levels. In non-DM hearts, epinephrine during underperfusion caused only a slight increase in LV stiffness though a similar low CPF to DM hearts. However, the reperfusion caused a marked increase in LV stiffness and a lower recovery of CPF. Epinephrine at constant low pressure, as well as norepinephrine at constant low flow rate, enhanced the ischemic injury, particularly in DM hearts, while aggravated the reperfusion injury in non-DM hearts.
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80
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Yamashita A, Arai T, Jun Ota, Asama H. Motion planning of multiple mobile robots for cooperative manipulation and transportation. ACTA ACUST UNITED AC 2003. [DOI: 10.1109/tra.2003.809592] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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81
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Yamashita A, Asada Y, Sugimura H, Yamamoto H, Marutsuka K, Hatakeyama K, Tamura S, Ikeda Y, Sumiyoshi A. 3P-0842 Contribution of von Willebrand factor to thrombus formation on neointima of rabbit stenotic iliac artery under high blood flow velocity. ATHEROSCLEROSIS SUPP 2003. [DOI: 10.1016/s1567-5688(03)91060-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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82
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Senda K, Kotoh K, Fukahara K, Furuta M, Yamashita A, Misaki T. [Off-pump coronary artery bypass grafting/beating coronary artery bypass grafting for a patient with low left ventricular ejection fraction]. KYOBU GEKA. THE JAPANESE JOURNAL OF THORACIC SURGERY 2002; 55:1129-32. [PMID: 12476563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
Beating coronary artery bypass grafting could be performed for a 47-year-old man with left ventricular ejection fraction (LVEF) of 9.3%. Post-operative LVEF was improved to 51.6%. Conventional coronary artery bypass grafting (CABG) used to be contraindicative for patients with LVEF below 20%. Recently, such patients are involved to indication of off-pump CABG (OPCAB) or beating CABG, because we consider OPCAB are lower complications than conventional CABG. We were able to bypass the circumflex for the patient while we had been used percutaneous cardio-pulmonary support (PCPS). We could perform beating coronary artery bypass grafting for a patient of the low LVEF.
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83
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Boschelli DH, Wang DY, Ye F, Yamashita A, Zhang N, Powell D, Weber J, Boschelli F. Inhibition of Src kinase activity by 4-anilino-7-thienyl-3-quinolinecarbonitriles. Bioorg Med Chem Lett 2002; 12:2011-4. [PMID: 12113830 DOI: 10.1016/s0960-894x(02)00302-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Based on a screening lead from a yeast-based assay to identify Src family kinase inhibitors, a series of 4-anilino-7-thienyl-3-quinolinecarbonitriles was prepared. When the thiophene ring was substituted with a water-solubilizing group in a 2,5-, 3,5- or 2,4-pattern, potent inhibition of Src kinase activity was observed.
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84
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85
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Yamashita A, Toy A, Scahill TA. Synthesis of khellin and its analogs via chromium carbene complexes. J Org Chem 2002. [DOI: 10.1021/jo00276a024] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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86
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Semmelhack MF, Yamashita A. Arene-metal complexes in organic synthesis: synthesis of acorenone and acorenone B. J Am Chem Soc 2002. [DOI: 10.1021/ja00538a046] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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87
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Yamashita A, Toy A, Ghazal NB, Muchmore CR. Reactions of alkylthio-substituted chromium carbene complexes with alkynes: application to synthesis of visnagan. J Org Chem 2002. [DOI: 10.1021/jo00280a002] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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88
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Semmelhack MF, Stauffer RD, Yamashita A. Reductions of conjugated carbonyl compounds with copper hydride - preparative and mechanistic aspects. J Org Chem 2002. [DOI: 10.1021/jo00439a015] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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89
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Brown CA, Yamashita A. Saline hydrides and superbases in organic reactions. IX. Acetylene zipper. Exceptionally facile contrathermodynamic multipositional isomeriazation of alkynes with potassium 3-aminopropylamide. J Am Chem Soc 2002. [DOI: 10.1021/ja00837a034] [Citation(s) in RCA: 169] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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90
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Semmelhack MF, Yamashita A, Tomesch JC, Hirotsu K. Total synthesis of confertin via metal-promoted cyclization-lactonization. J Am Chem Soc 2002. [DOI: 10.1021/ja00485a052] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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91
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Miyahara S, Nakajima K, Yamashita A, Kotoh K, Misaki T. [The treatment for the acute occlusion of a coronary artery by PTCA failure with the acute occlusion of a femoral artery by the IABP insertion]. KYOBU GEKA. THE JAPANESE JOURNAL OF THORACIC SURGERY 2002; 55:227-9. [PMID: 11889812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
A 68-year-old woman had the acute occlusion of a coronary artery by PTCA failure acute occlusion of a femoral artery by the IABP insertion. The patient underwent on pump beating coronary bypass and axillo-femoral bypass simultaneously.
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92
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Miyanishi K, Yamamoto T, Irisa T, Yamashita A, Jingushi S, Noguchi Y, Iwamoto Y. Bone marrow fat cell enlargement and a rise in intraosseous pressure in steroid-treated rabbits with osteonecrosis. Bone 2002; 30:185-90. [PMID: 11792583 DOI: 10.1016/s8756-3282(01)00663-9] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The etiology of steroid-induced osteonecrosis (ON) is unclear. This study was designed to determine whether bone marrow fat cell size, intraosseous pressure, and blood flow rate differed between steroid-treated rabbits with ON and those without. Twenty-nine rabbits were intramuscularly injected once with 20 mg/kg of methylprednisolone acetate (MPSL), and five rabbits were injected once with physiologic saline (PS) as a control. Intraosseous pressure and blood flow rate in the proximal femur were determined before and at 2 weeks after the injection. After these measurements, both femora and humeri were histopathologically examined for the presence of ON, and size of bone marrow fat cells were morphologically examined. At 2 weeks after steroid injection, the intraosseous pressure was significantly higher in rabbits with ON than in those without (p = 0.0251), and the blood flow rate had decreased significantly more in rabbits with ON than in those without (p = 0.0051). The size of the bone marrow fat cells was significantly (p = 0.0004) larger in rabbits with ON (diameter, 63.5 +/- 5.8 microm) than in those without (diameter, 53.3 +/- 6.9 microm). Injection of PS (5 rabbits), 1 (10 rabbits), 5 (10 rabbits), and 20 (10 rabbits) mg/kg of body weight of MPSL showed that a larger dose of steroid increased both fat cell size and prevalence of ON. These results suggest that bone marrow fat cell enlargement and a rise in intraosseous pressure may be important when considering the pathophysiology of steroid-induced ON in rabbits.
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93
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Kurosaki F, Yamashita A, Arisawa M. Determination of Ca(2+) influx across plant plasma membrane with sealed vesicles reoriented by Brij 58. Anal Biochem 2001; 299:266-8. [PMID: 11730354 DOI: 10.1006/abio.2001.5426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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94
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Uchiyama H, Kobayashi T, Yamashita A, Ohno S, Yabe S. Cloning and characterization of the T-box gene Tbx6 in Xenopus laevis. Dev Growth Differ 2001; 43:657-69. [PMID: 11737146 DOI: 10.1046/j.1440-169x.2001.00606.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Tbx6 is a member of the T-box gene family. Studies of knockout mice indicate that Tbx6 is involved in somite differentiation. In the present study, we cloned Tbx6 from another vertebrate species, namely Xenopus laevis, and studied its roles in development. The expression of Tbx6 in Xenopus started from the early gastrula stage, reached a peak during the late gastrula to neurula stages and then declined. Initial expression of Tbx6 was observed in the paraxial mesoderm during the gastrula stage. The Tbx6-expressing region spread anteriorly and ventrally in the neurula stage. In the tailbud stage, the area of expression shrank caudally and was finally restricted to the tip of the tailbud. Overexpression of Tbx6 mRNA in dorsal blastomeres caused atrophy of the neural tube and inhibited differentiation of the notochord. Animal cap explants overexpressing Tbx6 or Tbx6VP16 mRNA, but not Tbx6EnR mRNA, differentiated mainly into ventral mesodermal tissues. This suggests that Tbx6 is a transcriptional activator. Higher doses of Tbx6 or Tbx6VP16 mRNA caused hardly any muscular differentiation. However, coinjection of Tbx6 mRNA with noggin mRNA elicited marked muscle differentiation. These results suggest that Tbx6 is implicated in ventral mesoderm specification but is involved in muscle differentiation when acting together with the dorsalizing factor noggin.
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95
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Ichikawa S, Gu S, Yamashita A. Correlation of rectum-associated lymph nodules with the development of experimentally induced acute colonic inflammation in rats. J Gastroenterol Hepatol 2001; 16:1360-7. [PMID: 11851833 DOI: 10.1046/j.1440-1746.2001.02639.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
BACKGROUND AND AIMS The mechanisms of inflammation in ulcerative colitis occurring initially in the rectum and then extending throughout the colon are still unknown. The aim of this study is to investigate the correlation of rectum-associated lymph nodules (RALN) and the development of a dextran sulfate sodium-induced experimentally acute colonic inflammation in rats. METHODS We immunohistochemically analyzed the lymph nodules in the rectal region of rats using monoclonal antibodies to specific markers. RESULTS Rectum-associated lymph nodules resembled the Peyer's patches, where CD4+, CD8+ lymphocytes and Mar 1+ macrophages were observed. After the administration of dextran-sulfate sodium (DSS), RALN showed hypertrophy with an increase in the number of CD4+, CD8+, and interleukin (IL)-2R+ lymphocytes in the periphery, as well as Mar 1+ macrophages in the entire region. Concurrently, platelet/endothelin cell adhesion molecule-1 (PECAM-1+) blood vessels, including high-endothelial venules (HEV), were increased in number in the interfollicular areas. Furthermore, a number of small lymph nodules varying in size were observed in the upper region of the rectum. Some of them were initially confined to the lamina propria mucosae, and became large enough to extend deeper into the tela submucosa. These DSS-induced lymph nodules contained large numbers of CD4+ lymphocytes, IL-2R+ lymphocytes, and Mar 1+ macrophages. CONCLUSIONS The pathological changes of ulcerative colitis were well correlated with the development of both RALN and DSS-induced lymph nodules. The immunological reaction that occurred in DSS-induced lymph nodules is significantly associated with the expansion of colitis from the lower region of rectum to the upper region of rectum and colon.
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96
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Yamashita M, Yamashita A, Naitoh T, Oseen K, Wassersug RJ. [Motility of alimentary tract of tadpoles at stepwise change in temperature]. UCHU SEIBUTSU KAGAKU 2001; 15:282-3. [PMID: 11997643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
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97
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Ishikawa T, Kawakami M, Fukui M, Yamashita A, Urano J, Saito S. Novel [2,3]-Sigmatropic Rearrangement for Carbon−Nitrogen Bond Formation [J. Am. Chem. Soc. 2001, 123, 7734−7735]. J Am Chem Soc 2001. [DOI: 10.1021/ja0167912] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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98
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Kimura Y, Yu DG, Fujita A, Yamashita A, Murakami Y, Matsumoto K. Effects of erbium,chromium:YSGG laser irradiation on canine mandibular bone. J Periodontol 2001; 72:1178-82. [PMID: 11577949 DOI: 10.1902/jop.2000.72.9.1178] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Only relatively few reports have described the morphological effects on bone produced by erbium,chromium: yttrium,scandium,gallium,garnet (Er,Cr:YSGG) laser irradiation, and none has investigated the atomic changes or estimated the temperature increases involved. The objectives of this study were to investigate the morphological, atomic, and temperature changes in irradiated areas during and after laser irradiation, and to evaluate the cutting effect on canine mandibular bone in vitro. METHODS Two canine mandibular bones were cut into 3 to 5 cm pieces and irradiated by an Er,Cr:YSGG laser utilizing a water-air spray at 5 W and 8 Hz for 10 or 30 seconds. During and after laser irradiation, temperature increases in the irradiated areas were measured by thermography. The samples were then observed by stereoscopy and scanning electron microscopy to determine morphological changes and by energy dispersive x-ray spectroscopy to evaluate atomic alterations. RESULTS Regular holes or grooves having sharp edges and smooth walls were produced, but no melting or carbonization was observed. The maximum temperature increase was an average 12.6 degrees C for 30-second irradiation. The continuous time of a temperature increase of more than 10 degrees C was consistently less than 10 seconds. An atomic analytical examination revealed that the calcium:phosphorus ratio was not significantly changed between the lased and unlased areas (P>0.0 1). CONCLUSION These results showed that the Er,Cr:YSGG laser cuts canine mandibular bone effectively without burning, melting, or altering the calcium:phosphorus ratio of the irradiated bone.
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Yamashita A, Ohnishi T, Kashima I, Taya Y, Ohno S. Human SMG-1, a novel phosphatidylinositol 3-kinase-related protein kinase, associates with components of the mRNA surveillance complex and is involved in the regulation of nonsense-mediated mRNA decay. Genes Dev 2001; 15:2215-28. [PMID: 11544179 PMCID: PMC312771 DOI: 10.1101/gad.913001] [Citation(s) in RCA: 305] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Nonsense-mediated mRNA decay (NMD) is a conserved surveillance mechanism that eliminates imperfect mRNAs that contain premature translation termination codons (PTCs) and code for nonfunctional or potentially harmful polypeptides. We show that a novel phosphatidylinositol 3-kinase-related protein kinase, hSMG-1, is a human ortholog of a product of Caenorhabditis elegans smg-1, one of seven smg genes involved in NMD. hSMG-1 phosphorylates hUPF1/SMG-2 in vivo and in vitro at specific serine residues in SQ motifs. hSMG-1 can associate with hUPF1/SMG-2 and other components of the surveillance complex. In particular, overexpression of a kinase-deficient point mutant of hSMG-1, hSMG-1-DA, results in a marked suppression of the PTC-dependent beta-globin mRNA degradation; whereas that of wild-type hSMG-1 enhances it. We also show that inhibitors of hSMG-1 induce the accumulation of truncated p53 proteins in human cancer cell lines with p53 PTC mutation. Taken together, we conclude that hSMG-1 plays a critical role in NMD through the direct phosphorylation of hUPF1/SMG-2 in the evolutionally conserved mRNA surveillance complex.
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100
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Nogawa T, Kamano Y, Yamashita A, Pettit GR. Isolation and structure of five new cancer cell growth inhibitory bufadienolides from the Chinese traditional drug Ch'an Su. JOURNAL OF NATURAL PRODUCTS 2001; 64:1148-1152. [PMID: 11575946 DOI: 10.1021/np0101088] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Five new bufadienolides, 3beta-formyloxyresibufogenin (1), 19-oxobufalin (2), 19-oxodesacetylcinobufagin (3), 6alpha-hydroxycinobufagin (4), and 1beta-hydroxybufalin (5), have been isolated together with the previously known bufadienolides 6-20 from the Chinese traditional drug "Ch'an Su". The structures were elucidated employing spectroscopic methods. Bufadienolides 1-5 provided significant inhibitory activity against the KB and HL-60 cancer cell lines. In addition, bufadienolide 1 was found active against the MH-60 cancer cell line.
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