151
|
Chung JH, Im EK, Park HY, Kwon JH, Lee S, Oh J, Hwang KC, Lee JH, Jang Y. A novel uracil-DNA glycosylase family related to the helix-hairpin-helix DNA glycosylase superfamily. Nucleic Acids Res 2003; 31:2045-55. [PMID: 12682355 PMCID: PMC153747 DOI: 10.1093/nar/gkg319] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Cytosine bases can be deaminated spontaneously to uracil, causing DNA damage. Uracil-DNA glycosylase (UDG), a ubiquitous uracil-excising enzyme found in bacteria and eukaryotes, is one of the enzymes that repair this kind of DNA damage. To date, no UDG-coding gene has been identified in Methanococcus jannaschii, although its entire genome was deciphered. Here, we have identified and characterized a novel UDG from M.jannaschii designated as MjUDG. It efficiently removed uracil from both single- and double-stranded DNA. MjUDG also catalyzes the excision of 8-oxoguanine from DNA. MjUDG has a helix-hairpin-helix motif and a [4Fe-4S]-binding cluster that is considered to be important for the DNA binding and catalytic activity. Although MjUDG shares these features with other structural families such as endonuclease III and mismatch-specific DNA glycosylase (MIG), unique conserved amino acids and substrate specificity distinguish MjUDG from other families. Also, a homologous member of MjUDG was identified in Aquifex aeolicus. We report that MjUDG belongs to a novel UDG family that has not been described to date.
Collapse
|
152
|
Abstract
Reactive oxygen species are the major contributing factors to lung ischemia-reperfusion (IR) injury. In this study, we tested whether a water soluble antioxidant fullerene derivative [C(60)(ONO(2))(7 +/- 2)] attenuates IR lung injury. Young Wistar rats were divided into two groups: control and C(60)(ONO(2))(7 +/- 2). Under ventilation with 95% air-5% CO(2) gas mixture and a 2.5 cm H(2)O end-expiratory pressure, the isolated lungs were perfused with a physiological solution. The experimental protocol included three periods: baseline (10 min), ischemia (45 min) and reperfusion (60 min, ventilated with 95% O(2)-5% CO(2) gas mixture). Before and after ischemia, we measured pulmonary arterial pressure (Ppa), pulmonary venous pressure and lung weight (W). Then, pulmonary capillary pressure and filtration coefficient (K(fc)) were calculated. Ischemia caused increases in Ppa, W and K(fc) in the control group. For most cases, the above ischemia-induced increases were attenuated by the C(60)(ONO(2))(7 +/- 2) pretreatment. Our results suggest that the antioxidant C(60)(ONO(2))(7 +/- 2) attenuates IR-induced lung injury.
Collapse
|
153
|
Lee KH, Lee N, Lim S, Jung H, Ko YG, Park HY, Jang Y, Lee H, Hwang KC. Calreticulin inhibits the MEK1,2-ERK1,2 pathway in alpha 1-adrenergic receptor/Gh-stimulated hypertrophy of neonatal rat cardiomyocytes. J Steroid Biochem Mol Biol 2003; 84:101-7. [PMID: 12648529 DOI: 10.1016/s0960-0760(03)00006-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
In cardiac myocytes, stimulation of alpha(1)-adrenoceptor (AR) leads to a hypertrophic phenotype. The G(h) protein (transglutaminase II, TGII) is tissue type transglutaminase and transmits the alpha(1B)-adrenoceptor signal with GTPase activity. Recently, it has been shown that the calreticulin (CRT) down-regulates both GTP binding and transglutaminase activities of TGII. To elucidate whether G(h) mediates norepinephrine-stimulated intracellular signal transductions leading to activation of extracellular signal-regulated kinases (ERKs) and neonatal rat cardiomyocyte hypertrophy, we examined the effects of G(h) on the activation of ERKs and inhibitory effects of CRT on alpha(1)-adrenoceptor/G(h) signaling. In neonatal rat cardiomyocytes, norepinephrine-induced ERKs activation was inhibited by an alpha(1)-adrenoceptor blocker (prazosin), but not by an beta-adrenoceptor blocker (propranolol). Overexpression of the G(h) protein stimulated norepinephrine-induced ERKs activation, which was inhibited by alpha-adrenoceptor blocker (prazosin). Co-overexpression of G(h) and CRT abolished norepinephrine-induced ERKs activation. Taken together, norepinephrine induces hypertrophy in neonatal rat cardiomyocytes through alpha(1)-AR stimulation and G(h) is partly involved in norepinephrine-induced MEK1,2/ERKs activation. Activation of G(h)-mediated MEK1,2/ERKs was completely inhibited by CRT.
Collapse
|
154
|
Koo BH, Sohn YD, Hwang KC, Jang Y, Kim DS, Chung KH. Characterization and cDNA cloning of halyxin, a heterogeneous three-chain anticoagulant protein from the venom of Agkistrodon halys brevicaudus. Toxicon 2002; 40:947-57. [PMID: 12076649 DOI: 10.1016/s0041-0101(02)00091-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We report upon the isolation, characterization, and cDNA cloning of an anticoagulant protein, halyxin from Agkistrodon halys brevicaudus venom. The protein exists as a 29kDa protein, and is separated into three chains on SDS-PAGE under reducing conditions. However, we cloned only two cDNAs encoding halyxin from the cDNA library of the snake venom gland, on the basis of the determined amino acid sequences. The complete amino acid sequences were deduced from their nucleotide sequences and named halyxin A (129 amino acid residues) and B chain (123 amino acid residues). The deduced amino acid sequence of halyxin A chain corresponds to the two smaller chains. Thus, it is considered that halyxin A chain could be synthesized as a single-chain protein that is subsequently cleaved to yield the mature two-chain protein. The amino acid sequence of halyxin is similar to that of other snake venom proteins of the C-type lectin superfamily, and prolongs plasma-clotting time. In the presence of Ca(2+) ions, halyxin binds to coagulation factors IX, X, IXa, and Xa, but not to other vitamin K-dependent coagulation factors. It also inhibits factor Xa in a non-competitive manner but does not affect other activated coagulation factors.
Collapse
|
155
|
Hwang KC, Lee KH, Jang Y, Yun YP, Chung KH. Epigallocatechin-3-gallate inhibits basic fibroblast growth factor-induced intracellular signaling transduction pathway in rat aortic smooth muscle cells. J Cardiovasc Pharmacol 2002; 39:271-7. [PMID: 11791013 DOI: 10.1097/00005344-200202000-00014] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Daily green tea drinking showed preventive effects on the progression of atherosclerosis. Although epigallocatechin-3-gallate [EGCG] has anti-proliferative effects on various cells, relatively little is known about the molecular mechanisms of the anti-proliferative effects of EGCG. To determine whether the transduction signals and protooncogene expression were affected by EGCG, this study investigated the molecular mechanism of the anti-proliferative effects in basic fibroblast growth factor (bFGF)-stimulated rat aortic smooth muscle cells (RAoSMCs). EGCG inhibited the proliferative response stimulated by 10% fetal bovine serum dose dependently in RAoSMCs (median inhibitory concentration [IC50]: 28.4 x 10(-6) M ). EGCG also inhibited the migration of bFGF-stimulated RAoSMCs in a dose-dependent manner, showing that 21.8 x 10(-6) M of EGCG significantly inhibited the migration by 75 +/- 5% in comparison with bFGF-stimulated migration. In RAoSMCs, EGCG dramatically inhibited Ras activation and c-jun N-terminal kinase (JNK) activity without affecting protein kinase C expression. Induction of c-jun mRNA stimulated by bFGF was significantly reduced dose dependently up to 87.3 x 10(-6) M of EGCG. These results indicate that the anti-proliferative effect of EGCG on RAoSMCs is partly Ras/JNK mediated, independent of protein kinase C, and is attributable to the downregulation of c-jun expression.
Collapse
|
156
|
Lin HC, Hwang KC, Yang YH, Lin YT, Chiang BL. Risk factors of wheeze and allergy after lower respiratory tract infections during early childhood. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2001; 34:259-64. [PMID: 11825005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Lower respiratory tract infections (LRIs) during early childhood can lead to bronchial hyperreactivity or recurrent obstructive bronchitis. The role of LRIs in the pathogenesis of allergic diseases such as allergic rhinoconjunctivitis, atopic eczema, and bronchial asthma is less clear. The aim of this retrospective study was to determine the incidence of subsequent wheezing and atopy, and the known risk factors for allergic sensitization in 74 children hospitalized for acute LRIs of various etiologies from January 1994 through December 1994. Results showed that there are no differences in outcomes between patients with respiratory syncytial virus LRI, Chlamydia pneumoniae LRI, and LRIs caused by other agents. Although lower respiratory tract illnesses, especially those caused by respiratory syncytial virus during infancy, were associated with an increased risk of subsequent wheezing during early childhood, wheezing tended to disappear with increasing age in many children. This study also found recurrent episodes of wheezing during the first 5 years of life, and symptoms suggestive of allergic rhinoconjunctivitis were the only factors predictive of subsequent diagnosis of asthma for children who had LRIs during early childhood. In conclusion, this study suggests that prevention of recurrent wheezing LRIs and good control of allergic rhinoconjunctivitis is critical for preventing subsequent development of bronchial asthma.
Collapse
|
157
|
Eom YW, Yoo MH, Woo CH, Hwang KC, Song WK, Yoo YJ, Chun JS, Kim JH. Implication of the small GTPase Rac1 in the apoptosis induced by UV in Rat-2 fibroblasts. Biochem Biophys Res Commun 2001; 285:825-9. [PMID: 11453667 DOI: 10.1006/bbrc.2001.5233] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Exposure of mammalian cells to ultraviolet (UV) light elicits a cellular response and also lead to apoptotic cell death. However, the role of Rac, a member of Rho family GTPases, in the UV-induced apoptosis has never been examined. In UV-irradiated Rat-2 fibroblasts, nuclear fragmentation began to be observed within 2 h and the total viability of Rat-2 cells were only about 15% at 6 h following by UV irradiation, whereas the total viability in Rat2-Rac(N17) cells stably expressing RacN17, a dominant negative Rac1 mutant, was almost close to 67%. Pretreatment with SB203580, a specific inhibitor of p38 kinase, likewise attenuated UV-induced cell death, but PD98059, a MEK inhibitor, did not. Thus, Rac1 and p38 kinase appear to be components in the apoptotic signaling pathway induced by UV irradiation in Rat-2 fibroblasts. In addition, our results show that p38 kinase stimulation by UV is dramatically inhibited by RacN17, suggesting that p38 kinase is situated downstream of Rac1 in the UV signaling to apoptosis.
Collapse
|
158
|
Sohn YD, Lim HJ, Hwang KC, Kwon JH, Park HY, Chung KH, Cho SY, Jang Y. A novel recombinant basic fibroblast growth factor and its secretion. Biochem Biophys Res Commun 2001; 284:931-6. [PMID: 11409882 DOI: 10.1006/bbrc.2001.5076] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Basic fibroblast growth factor (FGF-2) is a pleiotropic mitogen which plays an important role in cell growth, differentiation, migration, and survival in different cells and organ systems. Recently, several clinical applications for FGF-2 gene transfer are being evaluated in wound healing and collateral artery development to relieve myocardial and peripheral ischemia due to the ability of FGF-2 to regulate the growth and function of vascular cells. However, FGF-2 lacks a classical hydrophobic secretion signal peptide, the FGF-2 chimeras containing various signal sequences have been explored. In this study, a novel recombinant 4sFGF-2 was constructed by replacing nine residues from the amino-terminus of native FGF-2 (Met1 to Leu9) with eight amino acid residues of signal peptide of FGF-4 (Met1 to Ala8) to better increase the secretion level of FGF-2. When the recombinant FGF-2 gene, cloned into the expression vector with CMV promoter, was expressed in COS-7 cells, the recombinant 4sFGF-2 was highly secreted into the media. The secreted 4sFGF-2 showed the same biological activity as the native FGF-2 in the dose-response effects on DNA synthesis and cell growth of rat aortic smooth muscle cells (RASMCs) and NIH3T3 cells. The 4sFGF-2 also was able to activate MAPK as wild FGF-2 in RASMCs. These results indicate that a novel recombinant 4sFGF-2 may be useful as clinical applicability of angiogenic growth factor gene transfer.
Collapse
MESH Headings
- 3T3 Cells
- Animals
- Aorta, Thoracic/cytology
- Aorta, Thoracic/drug effects
- Aorta, Thoracic/physiology
- COS Cells
- Cell Division/drug effects
- Cells, Cultured
- Chlorocebus aethiops
- Cloning, Molecular/methods
- DNA/biosynthesis
- Dose-Response Relationship, Drug
- Fibroblast Growth Factor 2/biosynthesis
- Fibroblast Growth Factor 2/genetics
- Fibroblast Growth Factor 2/pharmacology
- Fibroblast Growth Factor 4
- Fibroblast Growth Factors/genetics
- Fibroblast Growth Factors/pharmacology
- Fibroblasts/metabolism
- Humans
- Mice
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/physiology
- Polymerase Chain Reaction
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/pharmacology
- Rats
- Rats, Sprague-Dawley
- Recombinant Fusion Proteins/pharmacology
- Recombinant Proteins/biosynthesis
- Recombinant Proteins/pharmacology
- Reverse Transcriptase Polymerase Chain Reaction
- Skin/metabolism
- Transfection/methods
Collapse
|
159
|
Abstract
Alloxanthine-inhibited xanthine oxidase (XOD) was found to be photoreactivated by irradiation of light of wavelengths in the range of 340-430 nm. The enzyme activity can be fully controlled to be on or off by many dark-light cycles. Electron spin resonance measurement shows the appearance of the molybdenum (V) ion and the reduced form of flavin adenine dinucleotide (FADH.) radical signals after irradiation of the alloxanthine-XOD complex. Electronic-absorption spectrum also shows the bleaching of Fe/S and flavin adenine dinucleotide chromophores at 375 and 450 nm as well as broad-band absorption of FADH. in the range of 500-700 nm. The quantum yield of photoreactivation of the enzyme activity is approximately 0.06. A photoinduced intraenzyme electron-transfer model is proposed to rationalize the photoreactivation process.
Collapse
|
160
|
Lin HC, Hwang KC, Lee HJ, Tsai MJ, Ni YH, Chiang BL. Penicillamine induced lupus-like syndrome: a case report. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2000; 33:202-4. [PMID: 11045386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Several drugs have been suggested to cause lupus-like syndrome. However, penicillamine-induced lupus-like syndrome has only rarely been reported in patients with Wilson's disease. We describe a 6- year-old Taiwanese girl, with a diagnosis of Wilson's disease in November, 1997, who developed lupus-like syndrome 17 months after penicillamine treatment. After treatment with prednisolone and decrease in the dose of penicillamine, her symptoms subsided gradually. This is the first such case reported in a Taiwanese patient. Because the symptoms of drug-induced lupus (DIL) are nonspecific, subjective and variable, the diagnosis of DIL requires awareness of DIL-inducing potential of chronic medication.
Collapse
|
161
|
Samuel D, Kumar TK, Ganesh G, Jayaraman G, Yang PW, Chang MM, Trivedi VD, Wang SL, Hwang KC, Chang DK, Yu C. Proline inhibits aggregation during protein refolding. Protein Sci 2000; 9:344-52. [PMID: 10716186 PMCID: PMC2144545 DOI: 10.1110/ps.9.2.344] [Citation(s) in RCA: 195] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The in vitro refolding of hen egg-white lysozyme is studied in the presence of various osmolytes. Proline is found to prevent aggregation during protein refolding. However, other osmolytes used in this study fail to exhibit a similar property. Experimental evidence suggests that proline inhibits protein aggregation by binding to folding intermediate(s) and trapping the folding intermediate(s) into enzymatically inactive, "aggregation-insensitive" state(s). However, elimination of proline from the refolded protein mixture results in significant recovery of the bacteriolytic activity. At higher concentrations (>1.5 M), proline is shown to form loose, higher-order molecular aggregate(s). The supramolecular assembly of proline is found to possess an amphipathic character. Formation of higher-order aggregates is believed to be crucial for proline to function as a protein folding aid. In addition to its role in osmoregulation under water stress conditions, the results of this study hint at the possibility of proline behaving as a protein folding chaperone.
Collapse
|
162
|
|
163
|
Wang IC, Tai LA, Lee DD, Kanakamma PP, Shen CK, Luh TY, Cheng CH, Hwang KC. C(60) and water-soluble fullerene derivatives as antioxidants against radical-initiated lipid peroxidation. J Med Chem 1999; 42:4614-20. [PMID: 10579823 DOI: 10.1021/jm990144s] [Citation(s) in RCA: 221] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
C(60), vitamin E, and three C(60) derivatives (polar 1 and water-soluble C(3)/D(3)C(60)s) were examined for their antioxidant effects on prevention of lipid peroxidation induced by superoxide and hydroxyl radicals. The protection effect on lipid peroxidation was found to be in the sequence: C(60) >/= vitamin E > 1 > none, for liposoluble antioxidants, and C(3)C(60) >> D(3)C(60) > none, for water-soluble ones. Fluorescence quenching of PyCH(2)COOH (Py = pyrene) by both C(3)- and D(3)C(60)s shows that the Stern-Volmer constant, K(SV), is about the same for both quenchers in aqueous solution. Upon addition of liposomes, the fluorescence quenching becomes more efficient: 5-fold higher in K(SV) for C(3)C(60) than for D(3)C(60). When Py(CH(2))(n)()COOH (n = 1, 3, 5, 9, or 15) was incorporated in lipid membranes, the K(SV)s all were small and nearly equal for D(3)C(60) but were quite large and different for C(3)C(60) with the sequence: n = 1 < 3 < 5 < 9 < 15. The better protection effect of C(3)C(60) on lipid peroxidation than that of D(3)C(60) is attributed to its stronger interaction with membranes. Overall, the antioxidation abilities of the compounds examined were rationalized in terms of the number of reactive sites, the location of antioxidant in lipid membranes, and the strength of interactions between antioxidants and membranes.
Collapse
|
164
|
Yang CY, Cheng MF, Tsai SS, Hung CF, Lai TC, Hwang KC. Effects of indoor environmental factors on risk for acute otitis media in a subtropical area. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 1999; 56:111-119. [PMID: 9972922 DOI: 10.1080/009841099158178] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The objective of this study was to examine the relationship between indoor environmental factors and acute otitis media in a subtropical area. A case-control study was performed using participants from a prevalence survey that included 219 school children with acute otitis media and 219 age- and gender-matched controls. The study was confined to 4164 primary school children aged 6-12 yr attending 8 primary schools in Kaohsiung rural municipalities who participated in a prevalence study of the health effects of an indoor environment. An acute otitis media case was defined as a child with acute symptoms (presenting with earache, fever, irritability, and/or discharge from the ear) diagnosed by a physician in the previous year. Controls selected from the same school did not have chronic or acute respiratory illness or an ear-related illness during the same period. Information regarding the home environment was obtained using a structured written questionnaire, completed by the parents of the children. Of the many indoor environmental factors included in this study, only living in a home with indications of dampness (mold, flooding, home dampness) showed an association with acute otitis media. It was concluded that dampness in the home is a new public health issue in subtropical areas.
Collapse
|
165
|
Abstract
STUDY OBJECTIVES The objective of this study is to examine the relationship between indoor environmental factors and childhood asthma in a subtropical area. DESIGN A case-control study was performed using participants of a prevalence survey that included 165 schoolchildren with asthma and 165 age- and gender-matched control subjects. SETTING The study was confined to 4,164 schoolchildren aged 6 to 12 years attending eight primary schools in Kaohsiung County rural municipalities who participated in a prevalence study concerning the health effects of the indoor environment. PARTICIPANTS Cases (n=165) were defined as children with current asthma confirmed by a physician. Control subjects (n=165) were selected from the same school and class and matched for age and gender, and they did not have a previous diagnosis of asthma, history of physician-confirmed atopic diseases, persistent wheezing, cough, or phlegm, or reported chest illness, pneumonia, or bronchitis. MEASUREMENTS AND RESULTS Information regarding the home environment was obtained using a structured written questionnaire, completed by the parents of the children. Of the many indoor environmental factors included in this study, only home dampness showed an association with asthma (odds ratio=2.65). CONCLUSIONS We conclude that dampness in the home is a new public health issue in subtropical areas.
Collapse
|
166
|
Huang YL, Shen CK, Luh TY, Yang HC, Hwang KC, Chou CK. Blockage of apoptotic signaling of transforming growth factor-beta in human hepatoma cells by carboxyfullerene. EUROPEAN JOURNAL OF BIOCHEMISTRY 1998; 254:38-43. [PMID: 9652391 DOI: 10.1046/j.1432-1327.1998.2540038.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Transforming growth factor-beta (TGF-beta) has been shown to induce apoptosis in normal hepatocytes and hepatoma cells both in vivo and in vitro. However, the mechanism by which TGF-beta induces apoptosis is not clear. The antiapoptotic activity of antioxidants including N-acetyl-L-cysteine (Ac-Cys), ascorbic acid and a novel free radical scavenger, carboxyfullerene (C60) on TGF-beta-treated human hepatoma Hep3B cells was examined. Only the water-soluble hexacarboxylic acid derivative of C60 was found to prevent TGF-beta-induced apoptosis. Antiapoptotic activity of C60 correlated its ability to eliminate TGF-beta-generated reactive oxygen species (ROSs). However, C60 did not interfere with TGF-beta-activated PAI-1 promoter activity in the Hep3B cells. These results indicate that the signaling pathway of TGF-beta-induced apoptosis may be related to the generation of ROSs and may be uncoupled from the TGF-beta-activated gene promoter activity. Furthermore, the regioisomer of C60 with a C3 symmetry was more potent in protecting cells from apoptosis than that with a D3 symmetry, and the C3 isomer had stronger interactions with lipid bilayers than the D3 isomer. The spectroscopic analysis revealed that the C3 isomer had stronger interactions with artificial lipid bilayers than the D3 isomer. Therefore, our study indicates that C60 may interact with membrane to eliminate TGF-beta-induced ROSs and to prevent apoptosis occur in human hepatoma cells.
Collapse
|
167
|
Hwang KC, Gray CD, Sweet WE, Moravec CS, Im MJ. Alpha 1-adrenergic receptor coupling with Gh in the failing human heart. Circulation 1996; 94:718-26. [PMID: 8772694 DOI: 10.1161/01.cir.94.4.718] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND We recently demonstrated that Gh, which transfers the signal from the alpha 1-adrenergic receptor to the 69-kD phospholipase C, is the previously identified tissue-type transglutaminase (TGase II). The alpha 1-adrenergic receptor mediates actions of the sympathetic nervous system, including cardiac, arteriolar, and smooth muscle contractions. In human cardiac tissue, the expression of the alpha 1-adrenergic receptor is increased under pathophysiological conditions, but changes in the physiological response are small. Therefore, it has been suggested that the other components involved in the alpha 1-adrenergic receptor-mediated signaling pathway are probably altered. METHODS AND RESULTS Immunological and biochemical studies with nonfailling and failing human heart tissues revealed that the GTP-binding and TGase activities of human heart TGase II (hhG alpha n) are downregulated in both ischemic and dilated cardiomyopathic human heart. In ischemic cardiomyopathy, the alpha 1-adrenergic receptor number increased twofold (27.0 fmol/mg) compared with the nonfailing (12.8 fmol/mg) and the dilated cardiomyopathic (15.6 fmol/mg) heart tissues, but the coupling of hhG alpha h with the alpha 1-adrenergic receptor did not increase. The intrinsic activity of hhG alpha h, was greatly decreased in membrane fractions, whereas the cytosolic TGase activity was not changed. In the dilated cardiomyopathic human heart, these intrinsic enzyme activities of hhG alpha h were also downregulated in the membrane fraction, whereas the amount of hhG alpha h protein was greatly increased (2.8-fold) compared with the nonfailing heart. CONCLUSIONS The results of the present study clearly demonstrate that the alpha 1-adrenergic receptor in human heart couples with Gh (TGase II) and indicate that downregulation of hhG alpha h activity is associated with human cardiac failure but that the mechanism differs between ischemic and dilated cardiomyopathies.
Collapse
|
168
|
Baek KJ, Das T, Gray CD, Desai S, Hwang KC, Gacchui R, Ludwig M, Im MJ. A 50 KDa protein modulates guanine nucleotide binding of transglutaminase II. Biochemistry 1996; 35:2651-7. [PMID: 8611570 DOI: 10.1021/bi9522965] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Regulation of cellular response is an important mechanism for controlling cellular functions. The transmembrane signaling of the hormone receptors is regulated by GTP-binding proteins (GTPases) and their associated proteins. Our previous studies demonstrated that the bifunctional GTP-binding protein, G alpha h (transglutaminase II), consistently copurified with an approximately 50 kDa protein (G Beta h) which is dissociated from G alpha h upon activation with GTP gamma S or AlF4-. Present immunological and biochemical studies on the regulation of the GTPase cycle of G alpha h, which involves the alpha 1-adrenoceptor and 50 KDa G beta h, reveal that the 50 kDa protein is indeed a G alpha h-associated protein and down regulates functions of G alpha h. Thus, polyclonal antibody against G Beta h coimmunoprecipitates GDP-bound G alpha h but not the GDP-AlF4--bound form. The GTP gamma S binding and GTPase activity of G alpha h are inhibited in a G beta h concentration dependent manner. Supporting this notion, G beta h accelerated GTP gamma S release from G alpha h and changes the affinity of G alpha h from GTP to GDP. Moreover, the ternary complex preparation exhibits TGase activity that is inhibited in the presence of the alpha 1-agonist and GTP. The GTP gamma S binding by the ternary complex, consisting of the alpha 1-agonist, the receptor, and Gh, is also inhibited by G beta h. The inhibition of GTP gamma S binding with the ternary complex requires a > or = 2.7-fold higher concentration of G beta h than the G alpha h alone, indicating that the receptor enhances the affinity of G alpha h for GTP. In addition, G beta h copurifies with an alpha 1-agonist, adrenoceptor, and G alpha h ternary complex, showing that the complex is a heterotetramer. Our data also suggest that G beta h does not directly interact with alpha 1-adrenoceptor. These findings clearly demonstrate that G alpha h associates with a novel protein which modulates the affinity of G alpha h for guanine nucleotides and that the GDP-bound Gh is the ground state for the counterpart activator, the alpha 1-adrenoceptor, in this signaling system.
Collapse
|
169
|
Hwang KC, Gray CD, Sivasubramanian N, Im MJ. Interaction site of GTP binding Gh (transglutaminase II) with phospholipase C. J Biol Chem 1995; 270:27058-62. [PMID: 7592956 DOI: 10.1074/jbc.270.45.27058] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The GTP binding G alpha h (transglutaminase II) mediates the alpha 1B-adrenoreceptor signal to a 69-kDa phospholipase C (PLC). Thus, G alpha h possesses both GTPase and transglutaminase activities with a signal transfer role. The recognition sites of this unique GTP binding protein for either the receptor or the effector are completely unknown. A site on human heart G alpha h (hhG alpha h) has been identified that interacts with and stimulates PLC. Expressed mutants of hhG alpha h with deleted C-terminal regions lost the response to (-)-epinephrine and GTP and failed to coimmunoprecipitate PLC by the specific Gh7 alpha antibody. The interaction regions were further defined by studies with synthetic peptides of hhG alpha h and a chimera in which residues Val665-Lys672 of hhG alpha h were substituted with Ile707-Ser714 residues of human coagulation factor XIIIa. Thus, eight amino acid residues near the C terminus of hhG alpha h are critical for recognition and stimulation of PLC.
Collapse
|
170
|
Liu DL, Teng RJ, Ho MM, Hwang KC, Hwang LM. Human herpesvirus-6 associated hemophagocytic syndrome in beta-thalassemia: report of one case. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI ZA ZHI [JOURNAL]. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI 1995; 36:373-375. [PMID: 8607365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
An 8-month-old male infant with severe anemia and thrombocytopenia was brought to our hospital due to fever and pallor. The physical examination on admission showed pale conjunctivae, skin rash, lymphadenopathy and hepatosplenomegaly. Subsequent laboratory studies showed pancytopenia, impaired liver function, elevated lactate dehydrogenase level but without evidence of disseminated intravascular coagulation. Bone marrow aspiration demonstrated increased macrophages and prominent hemophagocytosis. The serological studies revealed a recent infection of human herpesvirus-6 which was confirmed by blood mononuclear cell culture and polymerase chain reaction. This infant was also found to have beta-thalassemia which was confirmed by hemoglobin electrophoresis performed before first transfusion. After treatment with intravenous immunoglobulin and other supportive therapies, the bone marrow abnormalities has completely recovered after 5 days, and the hemogram improved. This report demonstrates the human herpesvirus-6 as the etiology of hemophagocytic syndrome.
Collapse
|
171
|
Teng RJ, Ho MM, Wang PJ, Hwang KC. Trismus-pseudocamptodctyly syndrome: report of one case. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI ZA ZHI [JOURNAL]. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI 1994; 35:144-7. [PMID: 8184690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Trismus-pseudocamptodactyly syndrome is a rare neuromuscular disorder that manifests as a combination of hand, foot, and mouth anomalies. Limited range of motion for hands, feet, and mouth are typical presentations. A male term newborn baby was noted to have trismus, ulnar deviation of both wrist joints, limited stretch of digits during hand dorsiflexion but with full digital extension during volarflexion, and talipes equinovarus of the right foot. These anomalies were not seen in his parents. Hecht syndrome, or trismus-pseudocamptodactyly syndrome, was diagnosed with a negative result of electromyographic study.
Collapse
|
172
|
Hwang KC, Mauzerall D, Wagner RW, Lindsey JS. Synthesis of amphipathic porphyrins and their photoinduced electron transfer reactions at the lipid bilayer-water interface. Photochem Photobiol 1994; 59:145-51. [PMID: 8165233 DOI: 10.1111/j.1751-1097.1994.tb05014.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A one flask synthesis of cis-substituted amphipathic porphyrins is reported. These porphyrins were used to study electrostatic effects on photoinduced electron transfer across the lipid bilayer-water interface. A neutral porphyrin undergoes only dynamic interfacial electron transfer reactions irrespective of charge of the acceptor, although ionic strength effects indicate a negative charge on the porphyrin donor species. A dianionic porphyrin forms an interfacial static complex with a dicationic electron acceptor, methyl viologen, at low ionic strength. The electron transfer rate within the complex is slow, 10(5) approximately 10(6) s-1, which is attributed to a near orthogonal orientation between the donor and the acceptor pi orbitals.
Collapse
|
173
|
Teng RJ, Tsou Yau KI, Ho MM, Hwang KC, Lee CY. Postnatal growth of low birthweight neonates in Taiwan. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI ZA ZHI [JOURNAL]. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI 1993; 34:443-50. [PMID: 8296556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The postnatal growth pattern of four hundred and twenty five Chinese low birth-weight neonates was assessed. All those whose birthweight were below 2500 grams and survived for more than 180 days during the study period were included. The gestational age was between 26 and 40 weeks, and the birthweights were between 766 and 2496 grams, respectively. Infants were grouped according to 250-gram birth-weight categories. The mean age of the lowest weight, mean age of weight regain, and percentage of weight loss were calculated for each weight group and demonstrated an inverse correlation to the birthweight. The mean age of the lowest weight ranged between 2.72 and 6.62 days, mean weight loss was between 4.06 and 14.56%, and age of weight regain was between 4.93 and 17.15 days, respectively.
Collapse
|
174
|
Lu CP, Lee WJ, Ho MM, Hwang KC. Risk factors of coronary arterial aneurysm in Kawasaki disease. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI ZA ZHI [JOURNAL]. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI 1993; 34:173-80. [PMID: 8368064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
From April 1983 to August 1991, 70 cases of Kawasaki disease were admitted to Taiwan Provincial Tao-Yuan General Hospital. Fifty-seven patients treated with aspirin 80-100 mg/kg/day alone during the acute phase were followed by two-dimensional echocardiography for two weeks to two years. Twelve cases (21%) complicated with coronary arterial aneurysm (CAA) were referred as high risk group. Those who had no CAA were a low risk group. Stepwise discriminant analysis was performed to obtain risk factors of CAA based on clinical and early laboratory data. This yielded a classification accuracy of 75.4%. The combination of two parameters, white blood cell count and C-reactive protein, can be applied to early identify Kawasaki patients at high or low risk of CAA.
Collapse
|
175
|
Chang CA, Teng RJ, Yen SL, Chang S, Ho MM, Hwang KC. Congenital chylothorax managed by partial pleurodesis: report of one case. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI ZA ZHI [JOURNAL]. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI 1993; 34:211-5. [PMID: 8368069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Congenital chylothorax, a rare cause of respiratory distress in neonate, presented here with respiratory distress from two days of age. Thoracocentesis was performed at six days, revealing a clear fluid with high protein content. Thoracotomy was performed at the age of 33 days because of a profuse amount of chest tube drainage. A leak of chyle was found near the esophageal hiatus of the costophrenic angle. Partial pleurodesis was performed because of difficulty in identifying the exact leakage point. Respiratory status improved very quickly after the operation, and oral intake was well-tolerated during follow-up.
Collapse
|