451
|
Chang LS, Lin J, Chang CC. Improvement in the binding of cobrotoxin to microtiter plates by glutaraldehyde at neutral pH. BIOCHEMISTRY AND MOLECULAR BIOLOGY INTERNATIONAL 1994; 34:403-408. [PMID: 7849651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The coating of the wells of microtiter plates with cobrotoxin in Tris (pH 9.8) or PBS (pH 7.2) buffer was assessed by enzyme-linked immunoassay (ELISA). It was found that the poor binding in neutral buffer was improved by adding glutaraldehyde (GA), and the bound amount reached the same extent as that measured with alkali buffer. The optimal concentration of GA was approx. 0.02%. A decrease in optical density was observed with GA concentration higher than 0.02%. This may result from the modification of cobrotoxin by GA, which induced a decrease in the antigenicity of the cobrotoxin as revealed by competitive immunoassay. This study implies that the coating of physiological samples with GA for ELISA may be carried out with physiological buffers without the need to change the buffer to one of alkaline pH.
Collapse
|
452
|
Chiu HC, Chang CH, Jee SH, Chang CC, Wu YC. Human dermal papilla cells and outer root sheath cells: no follicular differentiation in nude mice and chicken embryos. J Formos Med Assoc 1994; 93:770-5. [PMID: 7735006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Human scalp specimens were incubated in 5 U/ml dispase solution at 4 degrees C overnight before the isolation of dermal papillae and follicle epithelium. This pretreatment not only facilitated the attachment and cell outgrowth of dermal papillae but also made it easier to pluck out hairs with intact follicle epithelium. The outer root sheath cells were released from the follicle epithelium and grown on a feeder layer of mitomycin C-treated human dermal fibroblasts. The subcultured outer root sheath cells were grown in a serum-free medium. When the mixtures of early-passage dermal papilla cells and outer root sheath cells were injected into the subcutis of nude mice, an epidermal cyst surrounded by layers of fibrous tissue was found in three weeks. No hair follicles were found when the mixtures were implanted onto the chorioallantoic membrane of nine-day-old chicken embryos. A keratinized mass lying on the chorionic epithelium with or without smaller similar masses in the chorioallantoic membrane was found in eight days. No hair follicle-like structure could be found. Possible factors contributing to the failure to undergo follicular differentiation in this study are discussed.
Collapse
|
453
|
Chang LS, Hung JJ, Lin S, Chang CC. Chemical modification of Lys-6 in Taiwan cobra phospholipase A2 with 4-chloro-3,5-dinitrobenzoate. BIOCHEMISTRY AND MOLECULAR BIOLOGY INTERNATIONAL 1994; 33:1207-13. [PMID: 7804147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Phospholipase A2 (PLA2) from Naja naja atra snake venom was modified with 4-chloro-3,5-dinitrobenzoate, and one major carboxydinitrophenylated (CDNP) PLA2 was separated by high performance liquid chromato-graphy. CDNP-PLA2 contained only one CDNP group on Lys-6 and showed a 93% drop in enzymatic activity. However, carboxydinitrophenylation did not significantly affect the secondary structure of the enzyme molecule as revealed by the CD spectra, and Ca2+ binding and antigenicity of CDNP-PLA2 were unaffected. Conversion of nitro groups to amino groups resulted in a partial restoration of enzymatic activity of CDNP-PLA2 to 35% of that of native enzyme. These results suggested that the positively charged side chain of Lys-6 played a role in the enzymatic mechanism of PLA2. However, the partial restoration in PLA2 activity reflects that a distortion of the active conformation arising from incorporation of a bulky CDNP group should occur.
Collapse
|
454
|
Zhang J, Chang CC, Lombardi L, Dalla-Favera R. Rearranged NFKB2 gene in the HUT78 T-lymphoma cell line codes for a constitutively nuclear factor lacking transcriptional repressor functions. Oncogene 1994; 9:1931-7. [PMID: 8208540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Rearrangements of the NFKB2 gene are associated with lymphoid malignancies, but the functional significance of these alterations is not known. Here we characterize structurally and functionally a rearranged NFKB2 gene identified at the T cell lymphoma line, HUT78. The rearrangement has truncated NFKB2 sequences within the 3' ankyrin domain, leading to the production of truncated mRNA species and proteins as detected by Northern blot and immunoprecipitation analysis, respectively. Cloning and sequencing of the corresponding cDNAs indicates that, via alternative splicing, the rearranged gene codes for two proteins of 84 and 85 kD (p84/85) which retain the DNA-binding rel domain and the first five ankyrin repeats, but have lost their carboxy-terminus including the seventh ankyrin repeat. Immunofluorescence and immunoprecipitation analysis of HUT78 cells indicate that p84/85 are abnormally located in the nucleus in an unprocessed form, suggesting that these proteins can escape the cytoplasmic retention typical of the normal NFKB2 p100 protein before it is processed into p52. Electrophoretic mobility shift assays performed on HUT78 nuclear extracts indicate that the abnormal NFKB2 proteins bind kappa B sites specifically and alter the composition of NF-kappa B complexes in HUT78 cells. Transient co-transfection assays involving NFKB2 expression vectors and kappa B-driven reporter plasmids indicate that NFKB2 p85 has lost the transcriptional repressor functions typical of normal NFKB2 p52. These data indicate that the NFKB2 gene rearrangement detected in HUT78 cells leads to the production of abnormal NFKB2 proteins capable of altering the function of the NF-kappa B transcription system. Since analogous rearrangements are found in lymphoid malignancies, these findings further support a role of NFKB2 alterations in tumorigenesis.
Collapse
|
455
|
Chang CC, Yu MW, Lu CF, Yang CS, Chen CJ. A nested case-control study on association between hepatitis C virus antibodies and primary liver cancer in a cohort of 9,775 men in Taiwan. J Med Virol 1994; 43:276-80. [PMID: 7523582 DOI: 10.1002/jmv.1890430315] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Most studies on the association between antibodies against hepatitis C virus (anti-HCV) and primary liver cancer (PLC) were limited to case-series, or cross-sectional case-control studies leaving a controversy on causal temporality. A nested case-control study on 38 newly-developed PLC patients and 152 matched controls selected from a cohort of 9,775 men in Taiwan recruited from September, 1984, to February, 1986, was carried out to examine the relation between HCV infection and PLC. Case-control pairs were matched on age (+/- 1 year), residence, and the date at recruitment. Serum samples collected from study subjects at the initial recruitment were examined for anti-HCV by enzyme immunoassay and hepatitis B surface antigen (HBsAg) by reverse passive hemagglutination assay combined with radioimmunoassay. History of cigarette smoking, alcohol consumption, vegetable consumption, vegetarian habit, and chronic liver diseases were also obtained through standardized interviews according to a structured questionnaire at the recruitment. After adjusting for HBsAg status and other risk factors, the anti-HCV was significantly associated with the development of PLC showing a multivariate-adjusted relative risk of 88.24. The results suggest that HCV infection may play an important role in the etiology of human PLC in Taiwan.
Collapse
|
456
|
Jenq W, Chen CL, Chang CC, Crang RF. Characterization of a major cell wall antigen and potential adhesin in three strains of Candida albicans. Arch Microbiol 1994; 162:33-40. [PMID: 8085915 DOI: 10.1007/bf00264370] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Selected strains of Candida albicans were examined to reveal the surface antigenicity and biochemical nature of major cell wall proteins that also were shown to serve as cellular adhesins on human buccal epithelial cells. Confirmation of the adhesive properties of these cells was made by scanning electron microscopy and immunofluorescence microscopy. Particular attention was directed at the clinical isolate KM-302. By means of indirect immunofluorescence staining, the KM-302 blastoconidia absorbed rabbit anti-C. albicans ATCC-32354 serum, revealing specific localization of surface antigens on germ tubes and pseudohyphae. Extracellular polymeric material and the cell wall extract of C. albicans KM-302 blastoconidia were found to contain a major surface antigen of 49 kDa that exhibited 42% adhesion inhibition in vitro. Of considerable significance is that immunogold localization by electron microscopy showed the antigen to be almost exclusively cell wall bound. This major antigen, identified in affinity and gel filtration chromatography fractions, was composed of 4% carbohydrate and 95.7% protein and had an isoelectric point of 6.1. The major antigen also showed a high level of similarity with that of C. albicans strain SC-5314 inasmuch as the major antigen of that strain had carbohydrate and protein compositions of 4 and 95.5%, respectively. Both of these strains also possessed the same percent of adhesion inhibition on human buccal epithelial cells.
Collapse
|
457
|
Abstract
A study was undertaken to examine the role of bacterial adherence in the development of infection at the site of an implant. The amount of in vitro adherence of Staphylococcus epidermidis was greatest for stainless steel, followed by polymethylmethacrylate and commercially pure titanium, and was least for polymethylmethacrylate with gentamicin. These materials then were preincubated with S. epidermidis and implanted. The number of organisms that were isolated and the rate of infection followed the same pattern as that in the in vitro studies. Materials that were not preincubated with bacteria also were implanted and bacteria were injected into the site. The number of organisms isolated from the site and the rate of infection were lower than those for the preincubated materials, but the trend was the same as in both the in vitro and the in vivo studies. The rates of infection and colonization correlated with the propensity for the organisms to adhere to a given material. Materials colonized with S. epidermidis at the time of implantation caused a high rate of infection. The ability of organisms to adhere to a material in vitro is correlated with their propensity to cause biomaterial-based infection.
Collapse
|
458
|
Trosko JE, Chang CC, Madhukar BV. The role of modulated gap junctional intercellular communication in epigenetic toxicology. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 1994; 14:303-312. [PMID: 8029502 DOI: 10.1111/j.1539-6924.1994.tb00245.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The normal development and health of all multicellular organisms, including the human being, depend on the adaptive maintenance of the integrity of the genetic information (e.g., DNA protective and repair mechanisms), as well as of the homeostatic and cybernetic regulatory systems within and between tissues. The primary focus of the past and current toxicological studies and risk assessment practices has been to ascertain and predict the "genotoxicity" of various physical and chemical agents. The paradigm of "carcinogen as mutagen," while valuable for stimulating studies of the detection of mutagens and of their potential role in "causing" somatic and germ line diseases, has tended to blunt research on the role of nongenotoxic mechanisms in disease causation. This brief analysis will emphasize the need to consider the role of modulated gap junctional intercellular communication (GJIC) in any biological risk assessment model. It is based on the following assumptions and facts. Because gap junctions exist in all metazoans, they have been associated with the regulation of cell proliferation, development, differentiation, and the adaptive function of both excitable and nonexcitable coupled cells. A highly evolutionarily conserved family of genes codes for proteins (connexins), which, as hexameric units (connexons), form membrane-associated channels of gap junctions. Cells coupled by gap junctions will have their ions and small regulatory molecules equilibrated. Regulation of GJIC can be at the transcriptional, translational, or posttranslational levels. Transient down or up regulation of GJIC can be induced by endogenous or exogenous chemicals via many mechanisms at any of these three levels. Stable abnormal regulation has been associated with activated oncogenes, and normal regulation has been associated with several tumor suppressor genes. The dysfunction of these gap junctions might play a role in the actions of various toxic chemicals that have cell type/tissue/organ specificity. This could bring about distinct clinical consequences, such as embryo lethality or teratogenesis, reproductive dysfunction in the gonads, neurotoxicity of the central nervous system, hyperplasia of the skin, and tumor promotion of initiated tissue. Modulation of GJIC should be viewed as a scientific basis of "epigenetic toxicology" because the alteration of intercellular communication would alter the internal physiological state of the cell. The inhibition of GJIC is a necessary component of mitogenesis (a necessary component of the multistage carcinogenic process). The modulation of GJIC can have both toxicological, as well as therapeutic potential.
Collapse
|
459
|
Liou HH, Chiang SS, Tsai SC, Chang CC, Wu SC, Shieh SD, Huang TP. Effect of intravenous calcitriol on secondary hyperparathyroidism in chronic hemodialysis patients. ZHONGHUA YI XUE ZA ZHI = CHINESE MEDICAL JOURNAL; FREE CHINA ED 1994; 53:319-24. [PMID: 8087705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND It has become evident that calcitriol can suppress parathyroid hormone (PTH) secretion by direct genomic actions. Intravenous calcitriol that bypasses gastrointestinal degradation might cause less degree of hypercalcemia and greater suppressive effect on PTH secretion. We investigated this PTH-suppressive effect of intravenous calcitriol in hemodialysis patients with secondary hyperparathyroidism. METHODS Calcitriol was administered at the end of each dialysis session three times a week in 20 uremic patients, for 12 weeks. RESULTS The mean dosage of calcitriol was 2.72 +/- 0.21 microgram per dialysis session. Serum intact PTH and C-PTH decreased (P < 0.05) after 6 weeks of treatment, while serum alkaline phosphatase (Alk-P) decreased 3 weeks later than PTH did. The individual maximal reduction of intact PTH, C-PTH and Alk-P were 77.80%, 67.36% and 45.98%. This PTH-suppression was dose-dependent. Despite the significant reduction of intact PTH by 58.17% after 6 weeks of treatment, no significant increase of serum calcium was found. An increase in serum calcium is not essential for this PTH-suppressive effect of calcitriol. Our observations thus provide another evidence to support the direct inhibitory effect of calcitriol on PTH secretion. Serum calcium, phosphorus, magnesium, albumin and osteocalcin levels did not change significantly. No side effect was found during treatment. CONCLUSIONS Intravenous calcitriol is effective and safe in treating hemodialysis patients with secondary hyperparathyroidism. This treatment is more important in patients who are intolerant to oral vitamin D supply and who are candidates for surgical parathyroidectomy.
Collapse
|
460
|
Chi WK, Ku CH, Chang CC, Tsai JN. Two-step cell disruption for the extraction of membrane-associated recombinant protein from Saccharomyces cerevisiae. Ann N Y Acad Sci 1994; 721:365-73. [PMID: 8010685 DOI: 10.1111/j.1749-6632.1994.tb47408.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The use of rDNA technology to express heterologous proteins has been very successful during the last several years. Choice of an expression host is very important in order to retain the biological activity of recombinant proteins. Baker's yeast, Saccharomyces cerevisiae, is a eucaryotic GRAS organism suitable for the expression of biologically active proteins. Specifically, hepatitis B surface antigen (HBsAg) is expressed in baker's yeast. Because the yeast cells need to be disrupted for the recovery of bioactive intracellular proteins and because the protein HBsAg is hydrophobic and has a tendency to become associated with cell membranes, the use of detergent increases the recovery yield. In order to remove most of the contaminants from yeast, a two-step disruption/extraction scheme has been developed that facilitates downstream processing. Furthermore, it also has the advantage of minimizing proteolytic actions on the recombinant protein by removing most of the contaminants and proteases into the supernatant during the first disruption step, while keeping the desired protein in the pellet fraction. Final recovery is then achieved by the extraction process. Parameters affecting the disruption/extraction processes have been discussed.
Collapse
|
461
|
Hasan MT, Chang CC, Chang TY. Somatic cell genetic and biochemical characterization of cell lines resulting from human genomic DNA transfections of Chinese hamster ovary cell mutants defective in sterol-dependent activation of sterol synthesis and LDL receptor expression. SOMATIC CELL AND MOLECULAR GENETICS 1994; 20:183-94. [PMID: 7940020 DOI: 10.1007/bf02254759] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We have isolated several non-leaky mutant Chinese hamster ovary (CHO) cell clones (M4, M19, and M21) requiring cholesterol and unsaturated fatty acid for growth. These mutants belong to the same complementation group as the mutant M1 cells previously reported from this laboratory. M19 cells reverted to lipid prototrophy at very low frequency and were chosen as recipients to perform DNA-mediated gene-transfer experiments using total human genomic DNAs. Biochemical characterization of these transfectant clones indicated that, unlike their parental M19 cells, they were able to exhibit activation of cholesterol biosynthesis and LDL receptor expression in response to sterol removal from the growth medium. RNA blotting analysis indicated that these transfectants were able to increase HMG-CoA synthase gene transcripts in response to sterol removal. From the genomic DNAs of a representative secondary transfectant cells, we cloned a unique human DNA fragment (designated as h lambda 2) and showed that h lambda 2 closely linked with the presumptive human M1 gene.
Collapse
|
462
|
Gomez J, Arnold RG, Bosted PE, Chang CC, Katramatou AT, Petratos GG, Rahbar AA, Rock SE, Sill AF, Szalata ZM, Bodek A, Giokaris N, Sherden DJ, Mecking BA, Lombard-Nelsen RM. Measurement of the A dependence of deep-inelastic electron scattering. PHYSICAL REVIEW. D, PARTICLES AND FIELDS 1994; 49:4348-4372. [PMID: 10017440 DOI: 10.1103/physrevd.49.4348] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
|
463
|
Chiou LC, Chang CC. Pharmacological relevance of peripheral type benzodiazepine receptors on motor nerve and skeletal muscle. Br J Pharmacol 1994; 112:257-61. [PMID: 8032647 PMCID: PMC1910319 DOI: 10.1111/j.1476-5381.1994.tb13060.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
1. Effects of agonists and antagonists of peripheral and central benzodiazepine receptors (pBZR and cBZR) on neuromuscular transmission were studied in mouse isolated phrenic nerve-diaphragm preparations. 2. Ro5-4864, a pBZR agonist, had no effect on the neuromuscular transmission but increased muscle contractility and antagonized the tetanic fade induced by neostigmine. 3. Ro5-4864 inhibited the regenerative tonic endplate depolarization caused by repetitive stimulation in the presence of neostigmine without affecting the amplitude and decay time of miniature and evoked single endplate potentials. 4. All the effects of Ro5-4864 were shared by PK11195, a pBZR antagonist, but not by clonazepam and flumazenil, a cBZR agonist and antagonist, respectively. 5. It is suggested that peripheral type benzodiazepine receptors modulate presynaptic function and muscle contraction.
Collapse
|
464
|
Naples D, Akchurin N, Birmingham P, Breuer H, Chang CC, Cihangir S, Corcoran MD, Davis WL, Gustafson HR, Holmgren H, Kasper P, Lincoln D, Longo MJ, Marraffino J, McPherson J, Miettinen HE, Morrow G, Mutchler GS, Onel Y, Thomas GP, Traynor MM, Waters JW, Webster MS, Xu JP, Zhu Q. A dependence of photoproduced dijets. PHYSICAL REVIEW LETTERS 1994; 72:2341-2344. [PMID: 10055855 DOI: 10.1103/physrevlett.72.2341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
465
|
Adams D, Ahmad S, Akchurin N, Birmingham P, Breuer H, Chang CC, Cihangir S, Corcoran MD, Davis WL, Gustafson HR, Holmgren H, Kasper P, Kruk J, Lincoln D, Longo MJ, Marraffino J, McPherson J, Miettinen HE, Morrow G, Mutchler GS, Naples D, Onel Y, Skeens J, Thomas GP, Traynor MM, Waters JW, Webster MS, Xu JP, Zhu Q. Observation of jet production by real photons. PHYSICAL REVIEW LETTERS 1994; 72:2337-2340. [PMID: 10055854 DOI: 10.1103/physrevlett.72.2337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
466
|
Bosted PE, Arnold RG, Chang CC, Gomez J, Katramatou AT, Martoff CJ, Petratos GG, Rahbar AA, Rock SE, Sill AF, Szalata ZM, Sherden DJ, Lambert JM, Lombard-Nelsen RM. Threshold inelastic electron scattering from the proton at high momentum transfers. PHYSICAL REVIEW. D, PARTICLES AND FIELDS 1994; 49:3091-3097. [PMID: 10017304 DOI: 10.1103/physrevd.49.3091] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
|
467
|
Jee SH, Lee SY, Chiu HC, Chang CC, Chen TJ. Effects of estrogen and estrogen receptor in normal human melanocytes. Biochem Biophys Res Commun 1994; 199:1407-12. [PMID: 8147884 DOI: 10.1006/bbrc.1994.1387] [Citation(s) in RCA: 85] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Normal human melanocytes were cultured selectively with F12 culture medium supplemented with growth hormones, phorbol ester and 1% of fetal calf serum. The estrogen receptors were analyzed using hydroxylapatite-column assay with tritiated 17-beta-estradiol as the binding ligand. Phenol red- free medium was used when the changes in cell numbers, melanin content and tyrosinase were assessed after incubating with physiological concentration of 17-beta estradiol (10(-12) and 10(-9) M). It was found that the melanocytes contained both cytosol (5.42 +/- 1.11 fmol/mg protein) and nuclear (59.13 +/- 17.12 fmol/mg protein) estrogen receptor. In response to estradiol, the cell number increased but both the melanin content and the tyrosinase activity decreased in a dose related pattern. These data suggested the presence of estrogen receptor with biological function in normal human melanocytes.
Collapse
|
468
|
Chang CC, Zhang J, Lombardi L, Neri A, Dalla-Favera R. Mechanism of expression and role in transcriptional control of the proto-oncogene NFKB-2/LYT-10. Oncogene 1994; 9:923-33. [PMID: 8108136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The NFKB-2 gene (previously LYT-10, NF-kappa Bp100 or NF-kappa Bp97) codes for a NF-kappa B/rel related protein which is highly homologous to NFKB-1 (previously NF-kappa Bp105) within its rel, poly-glycine and ankyrin domains. The NFKB-2 gene is a candidate proto-oncogene since it is involved in lymphoma-associated chromosomal aberrations. In order to gain insight into the physiological function and role in tumorigenesis of NFKB-2, we have analysed its mechanism of expression and role in transcriptional regulation. We report that, contrary to previous studies, a single 3.2 kb mRNA species and its 100 kD (p100) primary translation product is detectable in all cell types tested. A second NFKB-2 protein, p52, corresponding to the amino-terminal half (rel domain) of NFKB-2 p100, is detectable in the same cell types and derives from the post-translational processing of p100. While p100 is constitutively localized in the cytoplasm, NF-kappa B induction by TPA treatment of Hela cells is associated with cytoplasmic/nuclear translocation of NFKB-2 p52 and its appearance within DNA-binding NF-kappa B complexes. NFKB-2 p52 differs from NFKB-1p50 in its differential affinity for kappa B sequences: by itself it binds H2/HLA-kappa B sites more efficiently than HIV/IgK-kappa B sites, while it can bind both sites efficiently when complexed with Rel-A(p65). Transient co-transfection of expression and reporter plasmids in cells devoid of endogenous NF-kappa B activity showed that p52 has no intrinsic transcriptional activation capabilities: it can stimulate Rel-A(p65)-driven transcription by formation of p65/p52 heterodimers, whereas, overexpressed, it down-regulates p65-dependent transcription by formation of inactive p52/p52 homodimers. These results indicate that the NFKB-2 gene codes for an inducible NF-kappa B transcription factor with the capability of differentially regulating NF-kappa B transcription depending on its abundance in the nucleus.
Collapse
|
469
|
Chang LS, Chang CC. Biochemical regulation of the activity of gamma-glutamylcysteine synthetase from rat liver and kidney by glutathione. BIOCHEMISTRY AND MOLECULAR BIOLOGY INTERNATIONAL 1994; 32:697-703. [PMID: 7913645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Rat liver and kidney gamma-glutamylcysteine synthetase (gamma GCS) had similar catalytic properties and consisted of heavy and light subunits, but the molecular structure of the two enzymes was not the same as evidenced by the results of SDS-PAGE and disc gel electrophoresis. Unlike kidney enzyme, most of liver gamma GCS was in a reduced enzyme form which did not have disulfide linkage between heavy and light subunits. Although the oxidized form of the two enzymes which subunits were linked with disulfide bond(s) could be dissociated to a similar extent by GSH, liver gamma GCS was inhibited by GSH to a much greater extent. These results suggest that the relative sensitivity of the gamma GCS enzymes to inhibition by GSH might be related to the inherent dissociability of heavy and light subunit of gamma GCS.
Collapse
|
470
|
Chen LN, Liu CS, Chang CC. Isolation and characterization of a toxic phospholipase A2 from the venom of the Taiwan habu (Trimeresurus mucrosquamatus). Biotechnol Appl Biochem 1994; 19:61-73. [PMID: 8136082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A toxic phospholipase A2 (PLA2) was isolated from Taiwan-habu-snake (Trimeresurus mucrosquamatus) venom by sequential chromatographies on CM-52, Sephadex G-75 and S-Sepharose columns. This basic PLA2 has a single polypeptide with an estimated M(r) of 15,000. The PLA2 activity was Ca(2+)-dependent and inactivated by p-bromophenacyl bromide and its specific antibody. The toxic PLA2-induced myotoxic and direct haemolytic effects as well as respiratory distress in mice with an intraperitoneal LD50 of 1.17 micrograms/g body weight. The histological examination showed it caused haemorrhage and congestion in the viscera of mice. It was also cytotoxic to myeloma cells (NS-1), baby-hamster-kidney (BHK) cells and human umbilical endothelial cells. By neutralization experiments with a specific antibody against toxic PLA2, it was found that the enzymic activity of toxic PLA2 is essential for its myotoxicity, but it is not the only factor responsible for the lethal toxicity.
Collapse
|
471
|
Chang LS, Lin SR, Chang CC, Yang CC. The essentiality of B chain in stabilizing the structure of the A chain in beta 1-bungarotoxin from Bungarus multicinctus venom. JOURNAL OF PROTEIN CHEMISTRY 1994; 13:233-6. [PMID: 8060495 DOI: 10.1007/bf01891981] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The dynamic of Trp residue in beta 1-bungarotoxin (beta 1-Bgt), the A chain of beta 1-Bgt and phospholipase A2 (PLA2) was assessed by fluorescence measurement. Acrylamide quenching studies showed that the exposure degree of the Trp in PLA2 is higher than the Trp in beta 1-Bgt. The Trp of beta 1-Bgt had a higher accessibility for iodide, reflecting that the basic nature of the B chain might exert an attractive electrostatic force for iodide and increase the susceptibility of Trp in the A chain to iodide. Removal of the B chain of beta 1-Bgt did not significantly affect the exposure degree of Trp in the A chain. Alternatively, the polarity of the environment around the Trp and the hydrophobic character of ANS and substrate binding sites in the separated A chain changed. Measurement of Trp fluorescence with increasing temperature showed that the stability of structure of beta 1-Bgt was higher than those of the separated A chain and PLA2. These results suggest that the B chain might interact with the A chain and stabilize the conformation of the A chain in beta 1-Bgt.
Collapse
|
472
|
Chang CC, Noll WW, Nutile-McMenemy N, Lindsay EA, Baldini A, Chang W, Chang TY. Localization of acyl coenzyme A:cholesterol acyltransferase gene to human chromosome 1q25. SOMATIC CELL AND MOLECULAR GENETICS 1994; 20:71-4. [PMID: 8197480 DOI: 10.1007/bf02257489] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Acyl coenzyme A:cholesterol acyltransferase (ACAT) is an intracellular enzyme that catalyzes the formation of cholesterol esters from cholesterol and long-chain fatty acyl-coenzyme A. It is believed that ACAT plays a key role in lipoprotein metabolism and atherogenesis. Recently our laboratory succeeded in molecular cloning and functional expression of human macrophage ACAT cDNA. We have now mapped the ACAT gene to chromosome 1, band q25 by using fluorescence in situ hybridization to metaphase chromosomes, and by Southern blotting analysis of human--hamster somatic cell hybrid panels.
Collapse
|
473
|
Chang CC, Ruhl RA, Halpern GM, Gershwin ME. Building components contributors of the sick building syndrome. J Asthma 1994; 31:127-37. [PMID: 8175632 DOI: 10.3109/02770909409044816] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The sick building syndrome has been widely discussed from epidemiological perspectives. Although there is considerable difference in opinion regarding the concrete and objective evidence to support a distinct sick building syndrome and/or building-related illness, much data indicates that numerous variables within buildings can potentially influence human health. In this paper, we discuss in detail not only the potential and unique infectious diseases caused by Legionella, Pontiac fever, Q fever, and influenza, but also the data implicating noninfectious etiologies of sick building syndrome and building-related illnesses. In addition, the role of psychological factors, mass hysteria, and indoor pollution is discussed with respect to the nature of associations between exposure and symptoms. Finally, comparisons are made in different building construction types of old versus new buildings to highlight changes in modern construction that may have led to a putative increase in work-related symptomatology.
Collapse
|
474
|
Dalla-Favera R, Ye BH, Lo Coco F, Chang CC, Cechova K, Zhang J, Migliazza A, Mellado W, Niu H, Chaganti S. BCL-6 and the molecular pathogenesis of B-cell lymphoma. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 1994; 59:117-23. [PMID: 7587061 DOI: 10.1101/sqb.1994.059.01.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The results presented identify the first genetic lesion associated with DLCL, the most clinically relevant form of NHL. Although no proof yet exists of a role for these lesions in DLCL pathogenesis, the feature of the BCL-6 gene product, its specific pattern of expression in B cells, and the clustering of lesions disrupting its regulatory domain strongly suggest that deregulation of BCL-6 expression may contribute to DLCL development. A more precise definition of the role of BCL-6 in normal and neoplastic B-cell development is the goal of ongoing study of transgenic mice engineered either to express BCL-6 under heterologous promoters or lacking BCL-6 function due to targeted deletions. In addition to contributing to the understanding of DLCL pathogenesis, the identification of BCL-6 lesions may have relevant clinical implications. DLCL represent a heterogeneous group of neoplasms which are treated homogeneously despite the fact that only 50% of patients experience long-term disease-free survival (Schneider et al. 1990). The fact that BCL-6 rearrangements identify biologically and clinically distinct subsets of DLCL suggests that these lesions may be useful as markers in selection of differential therapeutic strategies based on different risk groups. Furthermore, the BCL-6 rearrangements can be used to identify and monitor the malignant clone with sensitive PCR-based techniques. Since clinical remission has been observed in a significant fraction of DLCL cases, these markers may serve as critical tools for sensitive monitoring of minimal residual disease and early diagnosis of relapse (Gribben et al. 1993).
Collapse
MESH Headings
- Animals
- B-Lymphocytes/metabolism
- Cell Differentiation/genetics
- Chromosomes, Human, Pair 3
- Cloning, Molecular
- DNA-Binding Proteins/genetics
- Gene Rearrangement
- Humans
- Lymphoma, B-Cell/etiology
- Lymphoma, B-Cell/genetics
- Lymphoma, Large B-Cell, Diffuse/classification
- Lymphoma, Large B-Cell, Diffuse/etiology
- Lymphoma, Large B-Cell, Diffuse/genetics
- Mice
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins c-bcl-6
- Proto-Oncogenes
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Transcription Factors/genetics
- Translocation, Genetic
Collapse
|
475
|
Chuang LY, Hung WC, Chang CC, Tsai JH. Characterization of apoptosis induced by transforming growth factor beta 1 in human hepatoma cells. Anticancer Res 1994; 14:147-52. [PMID: 8166442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Apoptotic cell death plays a major role in the regulation of cell growth and this process may be activated by different agents through various pathways. The present study aimed to elucidated the mechanism of apoptosis caused by transforming growth factor beta 1 (TGF-beta 1) in human hepatoma cells. Several biological parameters which were reported to be crucial in the induction of programmed cell death in other experimental systems were measured. We found that TGF-beta 1-induced cell death is independent of cytosolic calcium and protein kinase C. Insulin and tumor promotor can rescue hepatoma cells from apoptosis, but the effect is time-dependent. Our results highlight that different apoptotic signal transduction pathways exist in different cell types. Apoptosis induced by TGF-beta 1 provides a good model for the understanding of cell death and the development of new anti-cancer drugs. Apoptotic cell death (apoptosis or programmed cell death) in normal tissue is a biological phenomenon that maintains hemostasis of systems of the body under physiological conditions. The features of apoptosis include condensation of chromatin, blebbing of the cell surface, transient increase in buoyant density and fragmentation of chromatin by a specific endonuclease.
Collapse
|