ABSTRACT
BACKGROUND: Peroxiredoxins (Prx) play an important role in regulating cellular differentiation and proliferation in several types of mammalian cells. One mechanism for this action involves modulation of hydrogen peroxide (H2O2)-mediated cellular responses. This report examines the expression of Prx I and Prx II in thyroid cells and their roles in eliminating H2O2 produced in response to TSH. METHODS: The expression of Prx-I and Prx-II were quantiated in FRTL-5 after stimulation with Thyroid stimulating hormone (TSH), Forskolin (FSK), Methimazole (MMI) and hydrogen peroxide (H2O2). Transient transfections were carried out with FRTL-5 cells at 80% confluency and 20microgram of pCRprx I and pCRprx II or equivalent molar amounts of the pCR3.1TM basic vector. Transient transfection used an electroporation technique. Intracellular H2O2 was assayed in FRTL-5 cells with a fluorescent dye, 2', 7'-dichlorofluoresceindiacetate (DCFH-DA). Apoptosis of cells were evaluated by using an detection kit (Promega, Inc., Madison, WI). RESULTS: Prx I and Prx II are constitutively expressed in FRTL-5 thyroid cells. Prx I expression, but not Prx II expression, is stimulated by exposure to TSH and H2O2. In addition, methimazole (MMI) induces a high level of Prx I mRNA and protein in these cells. Overexpression of Prx I and Prx II enhance the elimination of H2O2 produced by TSH in FRTL-5 cells. Treatment with 500microM H2O2 causes apoptosis in FRTL-5 cells as evidenced by standard assays of apoptosis (i.e., terminal deoxynucleotidyl transferase deoxyuridine triphosphate-biotin nick end-labeling (TUNEL), BAX expression and PARP cleavage. Overexpression of Prx I and Prx II reduces the amount of H2O2-induced apoptosis measured by these assays. CONCLUSION: These results suggest that Prx I and Prx II are involved in the removal of H2O2 in thyroid cells, and can protect these cells from undergoing apoptosis. These proteins are likely to be involved in the normal physiological response to TSH-induced production of H2O2 in thyroid cells.
Subject(s)
Apoptosis , Colforsin , Deoxyuridine , DNA Nucleotidylexotransferase , Electroporation , Hydrogen Peroxide , Hydrogen , In Situ Nick-End Labeling , Methimazole , Molar , Peroxiredoxins , RNA, Messenger , Thyroid Gland , Thyrotropin , TransfectionABSTRACT
BACKGROUND: In the previous studies, we identified that the interferon-gamma activated sequence (GAS) in the 5-flanking region of rat ICAM-1 gene is major element for interferon-y-inducible expression of the gene in rat thyroid cells, FRTL-5. We here, investigated the role of transcriptional coactivators, CBP (CREB binding protein) and CIITA (class II transactivator) in the modulation of the activity of GAS which could interacts with signal transducers and activators of transcription-1 and 3 (STAT1 and STAT3). METHODS: The expression of CBP RNA and protein were quantitated in FRTL-5 after stimulation with interferon-y (IFN-gamma), thyroid stimulating hormone (TSH), forskolin and methimazole. Direct association of CBP with STAT were analyzed by irnmunoprecipitation. The transcriptional roles of CBP and CIITA in the regulation of GAS were assessed by the cotransfection with their expression vectors with reporters; 5-deletion constructs of rat ICAM-1 promoter or 8xGAS-luc constructs, into FRTL-5 thyroid cells. RESULTS: The level of CBP RNA and protein were not changed by the treatment with TSH, IFN-y, forskolin and methimazole in FRTL-5, FRT and BRL liver cells. The CBP could be directly associated with STAT1. Furthernmore, the overexpression of CBP significantly increases the both promoter activities; rat ICAM-1 gene promoter which has GAS element and 8xGAS-luc cassette constructs. However the cotransfection of CI1TA decreased the constitutive and CBP-mediated transactivation of rat ICAM-1 promoter and SxGAS-luc cassette constructs. CONCLUSION: We identified that the two transcriptional coactivators; CBP and CIITA has differential roles in the regulation of transcriptional activity of GAS drived promoter. CBP increases the GAS activity through the direct binding with STATl, but CIITA inhibited the CBP-mediated transactivation of GAS activity.
Subject(s)
Animals , Rats , Colforsin , Intercellular Adhesion Molecule-1 , Interferon-gamma , Liver , Methimazole , RNA , Thyroid Gland , Thyrotropin , Transcriptional Activation , TransducersABSTRACT
To investigate fragile sites induced by aphidicolin which is a specific inhibitor of eukaryotic DNA polymerase a which is primarily associated with chromosomal DNA replication in human lymphocytes, HaCat cells (human keratinocytes) and MRC-5 cells (human embryonic lung fibroblast), we cultured each cells in RPMI 1640 with 10% fetal calf serum and 2% PHA. Treatment of the cells with aphidicolin was generally carried out for the last 24 hours of culturing. The drug was dissolved in DMSO and used at final concentrations of 0.05~0.15 mg/ml, corresponding to a maximum DMSO concentration of 0.028%. Karyotypes of each cells were performed by routine method, and 50 metaphases were scored for each culture for analysis of breakage rate. Experimental cells treated with APC showed a dose dependent sensitivity and the amounts of chromosome breakage induced by APC are the highest in concentration of 0.15 mg/ml. The frequency of fragile sites on each cells appeared in MRC-5 cells, lymphocytes and HaCat cells in order. The common fragile sites on all experiments was 16q23, and the common fragile sites on embryonic cells was 1p31. It can be concluded that gene or nucleic acid which is located on 16q23 is the most important factor to induce chromosomal breakage with sensitivity to aphidicolin and 1p31 is important site to induce chromosomal breakage in embryonal cells.
Subject(s)
Humans , Aphidicolin , Chromosome Breakage , Dimethyl Sulfoxide , DNA , DNA Replication , Karyotype , Lung , Lymphocytes , MetaphaseABSTRACT
No abstract available.
ABSTRACT
For the study on the teratogenic effects and its mechanism of FUDR on the developing rat fetuses, Sprague -Dawley rats as experimental animal and 5 -fluoro -2 '-deoxyuridine (Sigma chemicals) as FUDR were used respectively. On the day of gestation 10.5, 60 mg/kg, 65 mg/kg and 70 mg/kg of FUDR was injected intraperitoneally, and sacrificed under ether anesthesia on the day of gestation 17.5. External congenital malformations such as hydrocephalus, lens defect, cleft palate, short tail, forelimb and hindlimb malformations were observed under stereoscope, and compared each other with control group. The results were as follows; 1. Congenital anomalies induced by FUDR were hydrocephalus, lens defect, cleft palate, short tail, and defects of extremities such as phocomelia, loss of first and second digits, undergrowth of digits, and syndactyly. 2. There is close relation between the rate of occurance of congenital anomalies and doses of FUDR in some organs. 3. There is significant differences between forelimbs and hindlimbs and between right forelimb and left forelimb in the rate of occurance of congenital anomalies of the extremities. According to the above results, it is considered that there is significant differences between the types and occurance rates of congenital anomalies induced by FUDR and the doses of FUDR. But distinct mechanism of action during teratogenesis of FUDR still remains unclear.
Subject(s)
Animals , Pregnancy , Rats , Anesthesia , Cleft Palate , Ectromelia , Ether , Extremities , Fetus , Floxuridine , Forelimb , Hindlimb , Hydrocephalus , Syndactyly , Tail , TeratogenesisABSTRACT
Bone materials diggd up from the Haemi nameless martyrdom holy place burial sites were severely broken into fragments of various size, clay matrix filled the bone marrow cavities, grass roots were spreaded into the periosteum and the fragments were very soft enough to be flaken. To make permanent specimens, bony fragments impregnated within unsaturated polyester resin with catalyzer MEKP, promotor 8% cobalt octoate, and UV absorber. Permanent specimens were so very transparent that all the macroscopic structures can be observed, and they were hard enough not to be broken or cracked. This method of preserving bony fragments is considered to be used in archaeologic preservation and in making teaching materials of various human organs or tissues.
Subject(s)
Humans , Bone Marrow , Burial , Cobalt , Methods , Periosteum , Poaceae , Polyesters , Teaching MaterialsABSTRACT
Accessory renal artery (ARA) is a kind of developmental anomaly in renal artery. It is important in respect to clinical medicine, for example primary hypertension, renovascular disease, inferior vena caval obstruction, ureteral obstruction, occurrence of other vascular anomalies such as accessory renal veins, surgical importance and renal transplantation. However, up to few research of ARA was reported in dissection of cadavers. In our dissecting theater, 12 accessory renal arteries for 10 cadavers were found during dissection the 22 cadavers from 1995 to 1996. 1. Two cases were bilateral and 8 cases were unilateral accessory renal arteries. 2. Seven cases were left and 5 cases were right accessory renal arteries. 3. Two cases originated at the abdominal aorta between celiac trunk and superior mesenteric artery, 7 cases originated between superior mesenteric artery and inferior mesenteric artery, and 3 cases originated below inferior mesenteric artery. 4. Seven cases have no branches during their courses, 4 cases have 3 branches, and a case has 2 branches. 5. Seven cases entered into renal parenchyma through renal hilum, 5 cases entered into apical and arterosuperior segments, and 6 cases entered into inferior segment.