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Zhang T, Lin Y, Han C, Jin J, Yao W. [Molecular cloning of rat OB gene and its expression in Escherichia coli]. WEI SHENG WU XUE BAO = ACTA MICROBIOLOGICA SINICA 1999; 39:215-9. [PMID: 12555537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
In order to provide rat OB gene product for studying the relationship between obesity and noninfectious diseases, rat OB cDNA was amplified by RT-PCR technique. 460 bp fragment of OB cDNA was subcloned into EcoRI/BamHI site of plasmid pUC 19. Sequence analysis of OB cDNA revealed that the translation reading frame was identical with that reported in the literature. Thereby plasmid pBV220-rOB was constructed and the specific expression of OB gene in E. coli identified by SDS-PAGE electrophoresis was obtained.
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Suzuki J, Kino Y, Uozumi T, Sano T, Teranishi T, Jin J, Soga K, Shiono T. Synthesis and functionalization of poly(ethylene-co-dicyclopentadiene). J Appl Polym Sci 1999. [DOI: 10.1002/(sici)1097-4628(19990404)72:1<103::aid-app11>3.0.co;2-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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678
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Zhao Z, Li S, Yan Y, Li Y, Yang M, Li D, Mu L, Huang W, Liu Y, Zai H, Jin J. The septal chondromucosal island pedicle flap: anatomic study and clinical application. Plast Reconstr Surg 1999; 103:1355-60. [PMID: 10190431 DOI: 10.1097/00006534-199904050-00003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A study was made of the facial regions of 10 fresh cadavers. The vascular anatomy of the perinasal region and the septum consistently confirmed the existence of a nasal alar basal artery and a nasal alar basal nerve to the septum. A new septal chondromucosal flap, supplied by the nasal alar basal artery and nerve, is proposed in this article. The composite flap can be used safely to restore partial or entire tarsoconjunctival defects of the upper or lower eyelid or combined defects of the upper and lower eyelid.
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679
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Mo S, Liu N, Jin J, Ding W, Ruan X, Qing H. [Influence of functional groups of huatanyuxin decoction on Ca2+ transmembrane influx in rat aorta]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1999; 24:232-3, 256. [PMID: 12205949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
OBJECTIVE To study the Ca2+ antagonistic effect of functional groups of Huatanyuxin decoction. METHOD The 45Ca transmembrane influx technique was used to measure the Ca2+ blocking effect of leak, receptor-operated Ca2+ channel (ROC) and potential-dependent Ca2+ channel (PDC) in rat aorta. RESULT ROC and PDC could be blocked when the complex prescription was used at concentrations of 0.5-5 mg/ml. Among the functional groups, Huoxue group (activating blood) and Xinqi group (promoting and normalizing flow of vital energy) showed better Ca2+ antagonistic effect. CONCLUSION The mechanism of therapeutic effect of Huatanyuxin decoction may be related to its Ca2+ blocking effect similar to verapamil.
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680
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Jin J. Treatment of spinal-cord-type cervical spondylosis by Chinese massotherapy. J TRADIT CHIN MED 1999; 19:52-3. [PMID: 10453585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
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681
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Jin J, Chang J, Chang JY, Kelley RF, Stafford DW, Straight DL. Factor VIIa's first epidermal growth factor-like domain's role in catalytic activity. Biochemistry 1999; 38:1185-92. [PMID: 9930978 DOI: 10.1021/bi981686z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Factor VIIa-tissue factor complex formation initiates the extrinsic blood coagulation pathway. We investigated factor VIIa's first epidermal growth factor-like (egf1) domain's role in the catalytic activity increase caused when factor VIIa binds tissue factor. Starting with a factor VIIa with factor IX's egf1 domain (factor VII(IXegf1)a), we made 4 proteins with egf1 residues changed to those in factor VIIa, including E51A, D64Q, FG74-75PA, and K79R. We measured each enzyme's affinity for tissue factor and determined the enzymes' kinetic constants with and without tissue factor. The Kd for factor VII(IXegf1)a binding to tissue factor was 60-200-fold higher than that of factor VIIa depending on the assay employed. Only factor VII(IXegf1)a with the K79R (K79Ra) mutation, among all the mutants, had an effect on binding with a Kd 3-8-fold lower than that of factor VII(IXegf1)a. In kinetic analyses with a small peptide substrate, in the absence of tissue factor, factor VIIa, factor VII(IXegf1)a, and K79Ra had similar kcat's and Km's. With tissue factor, due to a kcat decrease, factor VII(IXegf1)a's catalytic efficiency (kcat/Km) was 2-fold lower than factor VIIa's. K79Ra's catalytic efficiency was intermediate between those of factor VIIa and factor VII(IXegf1)a. With factor X as substrate, in the absence of tissue factor, K79Ra and factor VII(IXegf1)a had catalytic efficiencies 1.5-fold and 2-fold lower than that of factor VIIa. In contrast, with tissue factor and with factor X as substrate, due to higher Km's, factor VII(IXegf1)a and K79Ra had only 9% and 33% of factor VIIa's catalytic efficiency. Our results suggest the egf1 domain's role in tissue factor binding involves critical alignment of tissue factor with factor VIIa's catalytic domain. Proper alignment in turn promotes optimal catalytic activities.
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682
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Gao R, Jin J, Niu Y. [Potentiated effects of total saponins of Panax Ginseng on inhibition of leukemic cells by cytotoxic drugs]. ZHONGGUO ZHONG XI YI JIE HE ZA ZHI ZHONGGUO ZHONGXIYI JIEHE ZAZHI = CHINESE JOURNAL OF INTEGRATED TRADITIONAL AND WESTERN MEDICINE 1999; 19:17-9. [PMID: 11783253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To investigate the potentiated effects of total saponins of Panax Ginseng (TSPG) on inhibition of leukemic progenitor cells by cytotoxic drugs in acute myelocytic leukemia. METHODS Using bone marrow culture of colony forming unite-acute myeloid leukemia (CFU-AML) method, the sensitivity of leukemic cells obtained from 18 patients to homoharringtonin (HHr), cytarabine (Ara), adriamycin (Adr) and etoposide (VP-16) were detected separately. RESULTS TSPG alone (20 micrograms/ml) could stimulate proliferation of CFU-AML obviously, and increase the colony numbers by 37.98% over the non-TSPG control (P < 0.01). In the presence of TSPG, the inhibition rates of CFU-AML of HHr, Ara, Adr and VP-16 were 51.2%-62.0% respectively, which were significantly higher than 30.4%-47.4% of non-TSPG control (all P < 0.01). In the combination of TSPG with cytotoxic drugs, the leukemic progenitor cells became more sensitive to cytotoxic drugs, CFU-AML colony numbers at 1.84-2.23 fold as more as those of non-TSPG control were inhibited by HHr, Ara, Adr and VP-16. Sensitivity test of 17 among 72 drugs reversed from resistant (suppression rate less than 30%) to sensitive (suppression rate more than 30%) by TSPG. CONCLUSIONS TSPG could drive non-cycling leukemic progenitors to enter cell cycle, and thereby enhance their susceptibility to cytotoxic drugs.
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Rosen K, Rak J, Jin J, Kerbel RS, Newman MJ, Filmus J. Downregulation of the pro-apoptotic protein Bak is required for the ras-induced transformation of intestinal epithelial cells. Curr Biol 1998; 8:1331-4. [PMID: 9843689 DOI: 10.1016/s0960-9822(07)00564-7] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Anoikis is a form of programmed cell death induced in normal epithelial cells by detachment from the extracellular matrix [1] [2] [3]. In epithelial cells of the intestine and other organs, activated rasinduces resistance to anoikis [3] [4], but the actual molecular effectors directly involved in the apoptotic machinery that execute or block anoikis have not yet been identified. Bak, a pro-apoptotic member of the Bcl-2 family, is downregulated in a high proportion of colorectal tumours [5]. In addition, Bak is an important regulator of apoptosis in normal intestinal epithelial cells [6] [7]. Here, we show that activated rasinduces the downregulation of Bak in rat and human intestinal epithelial cells. This ras-induced downregulation of Bak expression could be suppressed by an inhibitor of phosphatidylinositol (PI) 3-kinase, an enzyme already implicated in ras-induced resistance to anoikis [8]. Ectopic expression of Bak in ras-transformed rat intestinal epithelial IEC-18 cells inhibited ras-induced resistance to anoikis and significantly reduced their tumorigenicity. We conclude, therefore, that the ability of rasto downregulate Bak, and the consequent resistance to anoikis, are essential components of the transforming capacity of this oncogene in intestinal epithelial cells.
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684
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Jin J, Dong W, Guarino LA. The LEF-4 subunit of baculovirus RNA polymerase has RNA 5'-triphosphatase and ATPase activities. J Virol 1998; 72:10011-9. [PMID: 9811739 PMCID: PMC110520 DOI: 10.1128/jvi.72.12.10011-10019.1998] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The baculovirus Autographa californica nuclear polyhedrosis virus encodes a DNA-dependent RNA polymerase that is required for transcription of viral late genes. This polymerase is composed of four equimolar subunits, LEF-8, LEF-4, LEF-9, and p47. The LEF-4 subunit has guanylyltransferase activity, suggesting that baculoviruses may encode a full complement of capping enzymes. Here we show that LEF-4 is a bifunctional enzyme that hydrolyzes the gamma phosphates of triphosphate-terminated RNA and also hydrolyzes ATP and GTP to the respective diphosphate forms. Alanine substitution of five residues previously shown to be essential for vaccinia virus RNA triphosphatase activity inactivated the triphosphatase component of LEF-4 but not the guanylyltransferase domain. Conversely, mutation of the invariant lysine in the guanylyltransferase domain abolished the guanylyltransferase activity without affecting triphosphatase function. We also investigated the effects of substituting phenylalanine for leucine at position 105, a mutation that results in a virus that is temperature sensitive for late gene expression. We found that this mutation had no significant effect on the ATPase or guanylyltransferase activity of LEF-4 but resulted in a modest decrease in RNA triphosphatase activity.
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685
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Guarino LA, Jin J, Dong W. Guanylyltransferase activity of the LEF-4 subunit of baculovirus RNA polymerase. J Virol 1998; 72:10003-10. [PMID: 9811738 PMCID: PMC110518 DOI: 10.1128/jvi.72.12.10003-10010.1998] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The baculovirus Autographa californica nuclear polyhedrosis virus encodes a DNA-dependent RNA polymerase that transcribes viral late genes. This polymerase is composed of four equimolar subunits, LEF-4, LEF-8, LEF-9, and p47. Here we present data indicating that the LEF-4 subunit of RNA polymerase is a guanylyltransferase. Incubation of RNA polymerase in the presence of divalent cation and radiolabeled GTP resulted in the formation of a covalent enzyme-guanylate complex that comigrated with the LEF-4 subunit. The label transfer assay showed an absolute requirement for divalent cation which could be satisfied by either manganese or magnesium. The reaction was specific for guanine nucleotides, and GTP was more effective than dGTP in the formation of enzyme-guanylate complex. To demonstrate that LEF-4 was the guanylyltransferase, the single subunit was overexpressed in baculovirus-infected cells. The overexpressed protein was primarily cytosolic, indicating that other proteins in the RNA polymerase complex were responsible for nuclear targeting of LEF-4. LEF-4 alone was able to covalently bind GMP, although less efficiently than viral RNA polymerase.
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686
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He Q, Wu B, Liao W, Jin J. [Determination algorithms in oscillometric blood pressure measurement]. SHENG WU YI XUE GONG CHENG XUE ZA ZHI = JOURNAL OF BIOMEDICAL ENGINEERING = SHENGWU YIXUE GONGCHENGXUE ZAZHI 1998; 15:369-72. [PMID: 12552782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
This paper discusses the method of oscillometric blood pressure determination. A new criterion for systolic pressure and diastolic pressure determination has been proposed, which is based on ratio changes of the oscillation amplitude under a wide normalized range. Primary experiment results show the new criterion is effective.
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687
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Murthy KS, Teng B, Jin J, Makhlouf GM. G protein-dependent activation of smooth muscle eNOS via natriuretic peptide clearance receptor. THE AMERICAN JOURNAL OF PHYSIOLOGY 1998; 275:C1409-16. [PMID: 9843699 DOI: 10.1152/ajpcell.1998.275.6.c1409] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In gastrointestinal smooth muscle, the neuropeptides vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) induce relaxation by interacting with VIP2/PACAP3 receptors coupled via Gs to adenylyl cyclase and with distinct receptors coupled via Gi1 and/or Gi2 to a smooth muscle endothelial nitric oxide synthase (eNOS). The present study identifies the receptor as the single-transmembrane natriuretic peptide clearance receptor (NPR-C). RT-PCR and Northern analysis demonstrated expression of the natriuretic peptide receptors NPR-C and NPR-B but not NPR-A in rabbit gastric muscle cells. In binding studies using 125I-labeled atrial natriuretic peptide (125I-ANP) and 125I-VIP as radioligands, VIP, ANP, and the selective NPR-C ligand cANP(4-23) bound with high affinity to NPR-C. ANP, cANP-(4-23), and VIP initiated identical signaling cascades consisting of Ca2+ influx, activation of eNOS via Gi1 and Gi2, stimulation of cGMP formation, and muscle relaxation. NOS activity and cGMP formation were abolished (93 +/- 3 to 96 +/- 2% inhibition) by nifedipine, pertussis toxin, the NOS inhibitor, NG-nitro-L-arginine, and the antagonists ANP-(1-11) and VIP-(10-28). NOS activity stimulated by all three ligands in muscle membranes was additively inhibited by Gi1 and Gi2 antibodies (82 +/- 2 to 84 +/- 1%). In reconstitution studies, VIP, cANP-(4-23), and guanosine 5'-O-(3-thiotriphosphate) stimulated NOS activity in membranes of COS-1 cells cotransfected with NPR-C and eNOS. The results establish a unique mechanism for G protein-dependent activation of a constitutive NOS expressed in gastrointestinal smooth muscle involving interaction of the relaxant neuropeptides VIP and PACAP with a single-transmembrane natriuretic peptide receptor, NPR-C.
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688
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Shin T, Tanuma N, Kim S, Jin J, Moon C, Kim K, Kohyama K, Matsumoto Y, Hyun B. An inhibitor of inducible nitric oxide synthase ameliorates experimental autoimmune myocarditis in Lewis rats. J Neuroimmunol 1998; 92:133-8. [PMID: 9916888 DOI: 10.1016/s0165-5728(98)00194-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We studied the effect of nitric oxide (NO) on experimental autoimmune myocarditis (EAC) in rats. We examined the role of inducible nitric oxide synthase (iNOS), an enzyme that produces NO, on hearts affected with EAC, by testing the effects of aminoguanidine (AG), a selective iNOS inhibitor, on the course of EAC. Western blotting detected iNOS in the affected cardiac tissues, but not in CFA immunized cases. Immunohistochemically, the majority of ED1+ macrophages in the EAC lesions were positive for iNOS and nitrotyrosine. A high dose of AG (200 mg/kg/day) significantly reduced the incidence of EAC (p < 0.05) and ameliorated the histological score for the cardiac inflammation (p < 0.01) compared with the low dose AG (100 mg/kg/day) and vehicle treated groups. The immunoblot analysis showed that a high dose of AG effectively suppressed iNOS in hearts affected with EAC. An iNOS band was barely detected in the high dose AG (200 mg/kg) treated group, while it was distinctively visualized in the vehicle and low dose AG (100 mg/kg) treated groups. These results suggest that iNOS is upregulated in EAC lesions and increased NO production plays an important role in the development of EAC. In addition, selective iNOS inhibitors may have a therapeutic role in treating certain autoimmune diseases including EAC.
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689
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Abstract
A DNA-dependent RNA polymerase was purified to homogeneity, starting from insect cells infected with the baculovirus Autographa californica nuclear polyhedrosis virus (AcNPV). The purified polymerase supported accurate and specific transcription from late and very late promoters but was not active on viral early promoters. Thus, promoter recognition is an integral function of the purified enzyme. The purified RNA polymerase was composed of only four equimolar subunits, which makes it the simplest DNA-directed RNA polymerase from a eukaryotic source described so far. Amino-terminal protein sequencing, peptide fingerprinting, and immunochemical analyses were used to identify the four subunits, all of which are virus encoded. Overexpression of the four viral proteins (LEF-8, LEF-4, LEF-9, and p47) in baculovirus-infected cells resulted in a significant increase in the levels of RNA polymerase produced in the infected cells. Thus, the overexpression data are consistent with our identification of the RNA polymerase subunits.
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690
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Coffer PJ, Jin J, Woodgett JR. Protein kinase B (c-Akt): a multifunctional mediator of phosphatidylinositol 3-kinase activation. Biochem J 1998; 335 ( Pt 1):1-13. [PMID: 9742206 PMCID: PMC1219745 DOI: 10.1042/bj3350001] [Citation(s) in RCA: 859] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
While a plethora of extracellular molecules exist that modulate cellular functions via binding to membrane receptors inside the cell, their actions are mediated by relatively few signalling mechanisms. One of these is activation of phosphatidylinositol 3-kinase (PI-3K), which results in the generation of a membrane-restricted second messenger, polyphosphatidylinositides containing a 3'-phosphate. How these molecules transduced the effects of agonists of PI-3K was unclear until the recent discovery that several protein kinases become activated upon exposure to 3'-phosphorylated inositol lipids. These enzymes include protein kinase B (PKB)/AKT and PtdIns(3,4, 5)P3-dependent kinases 1 and 2, the first two of which interact with 3'-phosphorylated phosphoinositides via pleckstrin homology domains. Once targeted to the membrane by this motif, PKB becomes phosphorylated at two residues, which relieves intermolecular inhibition, allowing the activated complex to dissociate and modify its targets. Identification of these substrates is the subject of intensive research, since at least one must play a key role in suppressing apoptosis, as demonstrated by expression of activated alleles of PKB. The generation of effective transdominant mutants, coupled with genetic analysis of the protein kinase in simpler organisms, should help in elucidating outstanding questions in the functions, targets and regulation of this important mediator of PI-3K signalling.
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691
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Shin T, Kim S, Tanuma N, Matsumoto Y, Moon C, Jin J. Mediation of apoptosis via inducible and constitutive nitric oxide synthase in autoimmune encephalomyelitis. J Neuroimmunol 1998. [DOI: 10.1016/s0165-5728(98)91487-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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692
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Jin J, Kunapuli SP. Coactivation of two different G protein-coupled receptors is essential for ADP-induced platelet aggregation. Proc Natl Acad Sci U S A 1998; 95:8070-4. [PMID: 9653141 PMCID: PMC20930 DOI: 10.1073/pnas.95.14.8070] [Citation(s) in RCA: 381] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
ADP is an important platelet agonist causing shape change and aggregation required for physiological hemostasis. We recently demonstrated the existence of two distinct G protein-coupled ADP receptors on platelets, one coupled to phospholipase C, P2Y1, and the other to inhibition of adenylyl cyclase, P2TAC. In this study, using specific antagonists for these two receptors, we demonstrated that concomitant intracellular signaling from both the P2TAC and P2Y1 receptors is essential for ADP-induced platelet aggregation. Inhibition of signaling through either receptor, by specific antagonists, is sufficient to block ADP-induced platelet aggregation. Furthermore, signaling through the P2TAC receptor could be replaced by activation of alpha2A-adrenergic receptors. On the other hand, activation of serotonin receptors supplements signaling through the P2Y1 receptor. Moreover, this mechanism of ADP-induced platelet aggregation could be mimicked by coactivation of two non-ADP receptors coupled to Gi and Gq, neither of which can cause platelet aggregation by itself. We propose that platelet aggregation results from concomitant signaling from both the Gi and Gq, a mechanism by which G protein-coupled receptors elicit a physiological response.
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693
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Lin M, Liu Y, Jin J. [Study on MDM2 and p53 gene proteins expression on acute leukemic cells and its correlation with chemotherapeutic efficacy]. ZHONGHUA XUE YE XUE ZA ZHI = ZHONGHUA XUEYEXUE ZAZHI 1998; 19:350-2. [PMID: 11189516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
OBJECTIVE To explore MDM2 and p53 gene proteins expression on human acute leukemia (AL) cells and their predictive value for chemotherapeutic efficacy. METHODS MDM2 and p53 gene proteins expression was assayed by immunohistochemical staining. RESULTS 1. The expression rates of MDM2 and p53 gene proteins were 71.7% and 21.7% respectively in 46 AL patients. The rates were slightly higher in relapse/refractory AL than in previously untreated AL; there was no difference among AL subtypes. 2. MDM2+ and p53- accounted for 67.4%, while the uniform expression of MDM2 and p53 15.2% (P < 0.01). 3. The marrow complete remission (CR) rate (69.2%) of MDM2- patients was higher than that (33.3%) of MDM2+ patients (P < 0.05). 4. Two of 4 patients with MDM2+++ gained CR and then MDM2 turned negative. CONCLUSION MDM2 gene protein was negatively related with p53 gene protein in AL cells. Different expression patterns of the two gene proteins could influence the therapeutic efficacy, and combined detection of the two may be used as a prognostic parameter for AL patients.
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694
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Chang J, Jin J, Lollar P, Bode W, Brandstetter H, Hamaguchi N, Straight DL, Stafford DW. Changing residue 338 in human factor IX from arginine to alanine causes an increase in catalytic activity. J Biol Chem 1998; 273:12089-94. [PMID: 9575152 DOI: 10.1074/jbc.273.20.12089] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
This study was designed to identify functionally important factor IX (FIX) residues. Using recombinant techniques and cell culture, we produced a mutant FIX with arginine at 338 changed to alanine (R338A-FIX). This molecule had approximately 3 times greater clotting activity than that of wild type FIX (wt-FIX) in the activated partial thromboplastin assay. R338A-FIX reacted normally with a panel of three FIX specific monoclonal antibodies and migrated on sodium dodecyl sulfate-polyacrylamide gels indistinguishably from wt-FIX. Using functional assays, we determined that R338A-FIXa's Kd for factor VIIIa (FVIIIa) was similar to that of wt-FIXa. Our kinetic analysis, using factor X as substrate, indicated that the mutation's major effects were a 3-fold increase in kcat and a 2-fold decrease in Km both manifested only in the presence of FVIIIa. R338A-FIXa's increased catalytic efficiency did not result from ablation of a thrombin sensitive site, reported to occur at arginine 338, since in our assays the thrombin inhibitor, hirudin, had no effect on activity of either wt-FIXa or R338A-FIXa. R338A-FIXa and wt-FIXa had equal activity, with or without FVIIIa, toward the synthetic substrate, methylsulfonyl-D-cyclohexylglycyl-arginine-p-nitroanilide. Interestingly, R338A-FIXa had reduced affinity for heparin. Therefore, we propose that R338A-FIXa's increased activity is not due to an allosteric effect on the active site, but that the Arg-338 residue is part of an exosite that binds both factor X and the mucopolysaccharide, heparin.
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695
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Gong M, Jin J, Guarino LA. Mapping of ORF121, a factor that activates baculovirus early gene expression. Virology 1998; 244:495-503. [PMID: 9601517 DOI: 10.1006/viro.1998.9116] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The protein product of the 39k gene of Autographa californica nuclear polyhedrosis virus is thought to be important for viral replication because of its association with the virogenic stroma and its role in activation of late gene expression Transient expression assays showed that addition of a DNA fragment encoding a 58-amino-acid polypeptide increased expression of a 39k reporter plasmid. This stimulation was dependent on cotransfection of a plasmid encoding IE1. Cotransfection of this gene, orf121, also stimulated ie1 expression, and the activation of ie1 was even more dramatic in the presence of IE1. These data suggested that ORF-121 stimulated 39k expression by upregulation of IE1 expression. Activation of 39k by ORF121 and the viral transcription factor IE2 was additive, while activation by ORF-121 and the apoptotic suppressor P35 was synergistic. Cotransfection of p39cat and pIE1 with plasmids encoding ORF121, IE2, and P35 stimulated 39cat expression more than 100-fold compared to cells transfected with only p39cat and pIE1. These data suggest that IE2 and ORF121 work by similar mechanisms and indirectly activate p39cat by increasing IE1 expression, while P35 increases 39cat expression by a different mechanism.
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696
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Staveley BE, Ruel L, Jin J, Stambolic V, Mastronardi FG, Heitzler P, Woodgett JR, Manoukian AS. Genetic analysis of protein kinase B (AKT) in Drosophila. Curr Biol 1998; 8:599-602. [PMID: 9601646 DOI: 10.1016/s0960-9822(98)70231-3] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The decision between survival and death is an important aspect of cellular regulation during development and malignancy. Central to this regulation is the process of apoptosis, which is conserved in multicellular organisms [1]. A variety of signalling cascades have been implicated in modulation of apoptosis, including the phosphatidylinositol (Pl) 3-kinase pathway. Activation of Pl 3-kinase is protective, and inhibition of this lipid kinase enhances cell death under several conditions including deregulated expression of c-Myc, neurotrophin withdrawal and anoikis [2-7]. Recently, the protective effects of Pl 3-kinase have been linked to its activation of the pleckstrin homology (PH)-domain-containing protein kinase B (PKB or AKT) [8]. PKB/AKT was identified from an oncogene, v-akt, found in a rodent T-cell lymphoma [9]. To initiate a genetic analysis of PKB, we have isolated and characterized a Drosophila PKB/AKT mutant (termed Dakt1) that exhibits ectopic apoptosis during embryogenesis as judged by induction of membrane blebbing, DNA fragmentation and macrophage infiltration. Apoptosis caused by loss of Dakt function is rescued by caspase suppression but is distinct from the previously described reaper/grim/hid functions. These data implicate Dakt1 as a cell survival gene in Drosophila, consistent with cell protection studies in mammals.
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697
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Shin T, Jin J, Kim J, Kim H, Lee C. Immunohistochemical study of protein kinase C in the testes of cattle and pigs. J Vet Med Sci 1998; 60:631-3. [PMID: 9637300 DOI: 10.1292/jvms.60.631] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We investigated the expression of novel protein kinase C (PKC) delta and theta in the testes of pigs and cattle using Western blot and immunohistochemical analysis. PKC delta and theta are recognized in the testes of pigs and cattle by Western blot analysis. We found in immunohistochemical study that PCK delta was localized in the spermatids of seminiferous tubules, but not in the interstitial cells, while PKC theta was recognized only in the interstitial cells of the testes of in both species. These findings suggest that PKC delta and theta play an important role in the development of spermatozoa and the regulation of androgen in the testicular interstitial cells (probably Leydig cells), respectively.
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698
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Zachor DA, Moore JF, Jin J, Theibert AB, Percy AK. C-fos mediates cocaine inhibition of NGF-induced PC12 cell differentiation. Mol Genet Metab 1998; 64:62-9. [PMID: 9682220 DOI: 10.1006/mgme.1998.2699] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In utero cocaine exposure can affect CNS development. Previous studies showed that cocaine inhibits neuronal differentiation in a dose-dependent fashion, in nerve growth factor (NGF)-stimulated PC12 cells, without affecting cell viability. NGF activates intracellular signaling proteins, specific immediate-early genes (IEG) including a transient peak of c-fos expression, and induction of late genes expression, leading to the neuronal phenotype. We hypothesized that cocaine interferes with NGF signaling. Therefore, we examined the pattern of c-fos expression in our cellular model. Time course of c-fos expression up to 72 h was determined in cells treated with NGF 20 ng/ml and cocaine 10 microgram/ml (a moderately toxic level) by RT-PCR analysis. Total RNA was isolated from cells, and levels of c-fos mRNA were estimated using gene-specific primers. In both control and experimental conditions, c-fos level was maximal at 0.5 h. In the control cells, c-fos expression declined rapidly to less than 5% of the 0.5h value, while in the cocaine-treated cells, c-fos level persisted through the 72-h exposure. Adding c-fos antisense to cells treated with NGF and cocaine resulted in significant improvement of neurite out-growth, from 28% (NGF + cocaine) to 89% (NGF + cocaine + c-fos antisense) of control differentiation after 72 h of exposure (Dunnet's T < 3.24). Inhibitory effects of cocaine on NGF-induced PC12 differentiation may be attributed to alteration of c-fos expression. Further studies will be required to examine the role of D1 receptor activation in mediating c-fos expression and to explore the effects of cocaine on other IEGs.
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699
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Jin J, Dasari VR, Sistare FD, Kunapuli SP. Distribution of P2Y receptor subtypes on haematopoietic cells. Br J Pharmacol 1998; 123:789-94. [PMID: 9535005 PMCID: PMC1565225 DOI: 10.1038/sj.bjp.0701665] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
1. RT-PCR-southern hybridization analyses with radiolabelled P2Y receptor cDNAs as probes indicated that the peripheral blood leukocytes and the human umbilical vein endothelial cells express P2Y1, P2Y2, P2Y4 and P2Y6 receptors. 2. Of the haematopoietic cell lines tested, promonocytic U937 cells express P2Y2 and P2Y6, but not P2Y1 or P2Y4; promyelocytic HL-60 cells express the P2Y1, P2Y2 and P2Y6 receptors but not the P2Y4 receptor; K562 cells express P2Y1 but not P2Y2, P2Y4 or P2Y6; and Dami cells express P2Y1, P2Y2, P2Y4 and P2Y6 receptors. 3. Of the peripheral blood leukocytes tested, polymorphonuclear cells express P2Y4 and P2Y6 but not P2Y1 or P2Y2 receptors; monocytes express P2Y1, P2Y2, P2Y4 and P2Y6 receptors and lymphocytes express P2Y1, P2Y2, P2Y4 and P2Y6 receptors. 4. These results suggest a physiological role for different P2Y receptor subtypes in the extracellular nucleotide-mediated stimulation of monocytes, neutrophils, lymphocytes and endothelial cells.
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700
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Li S, Chen Z, Jin J. [The morphological and functional changes of pulmonary intravascular macrophages induced by LPS]. ZHONGHUA JIE HE HE HU XI ZA ZHI = ZHONGHUA JIEHE HE HUXI ZAZHI = CHINESE JOURNAL OF TUBERCULOSIS AND RESPIRATORY DISEASES 1998; 21:167-9. [PMID: 11263355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
OBJECTIVE To study the roles of pulmonary intravascular macrophages (PIMs) on infective acute lung injury (ALI). METHOD Porcine pulmonary blood vessels were flushed by modified Morton's method, PIMs were isolated by adhesion method and identified with the features at both light and electron microscopic level. The activity of IL-1 beta, and content of IL-6, IL-8 and TNF alpha in the culture supernatants were measured by thymocyte proliferation or ELISA, respectively. RESULT Enlarged and increased pseudopods, and increased amount of lysosomes and phagosomes were found in the PIM stimulated with lipopolysaccharide (LPS, 10 micrograms/ml); the releases of TNF alpha, IL-1 beta, IL-6 and IL-8 were increased significantly as compared with the level of pre-stimulation of LPS (P < 0.01), and reaching their peaks at 1 h, 2 h, 4 h and 6 h after LPS stimulation, respectively. CONCLUSION The isolation of porcine PIMs can be completed with modified Morton's method; the phagocytosis and secretion of PIMs are more active after LPS stimulation. In the pathogenesis of ALI, TNF alpha and IL-1 beta may play an important role at its early stage; however, the IL-6 and IL-8 may be associated with the pathophysiological changes at the later stage of ALI.
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