Troglitazone Inhibits Matrix Metalloproteinase-9 Expression and Invasion of Breast Cancer Cell through a Peroxisome Proliferator-Activated Receptor γ-Dependent Mechanism / 한국유방암학회지

PURPOSE: Peroxisome proliferator-activated receptor γ (PPARγ) is involved in the pathology of numerous diseases including atherosclerosis, diabetes, obesity, and cancer. Matrix metalloproteinases (MMPs) play a significant role in tissue remodeling related to various processes such as morphogenesis, angiogenesis, tissue repair, invasion, and metastasis. We investigated the effects of PPARγ on MMP expression and invasion in breast cancer cells. METHODS: MCF-7 cells were cultured and then cell viability was monitored in an MTT assay. Western blotting, gelatin zymography, real-time polymerase chain reaction, and luciferase assays were performed to investigate the effect of the synthetic PPARγ ligand troglitazone on MMP expression. Transcription factor DNA binding was analyzed by electrophoretic mobility shift assay. A Matrigel invasion assay was used to assess the effects of troglitazone on MCF-7 cells. RESULTS: Troglitazone did not affect MCF-7 cell viability. 12-O-tetradecanoylphorbol-13-acetate (TPA) induced MMP-9 expression and invasion in MCF-7 cell. However, these effects were decreased by troglitazone. TPA increased nuclear factor κB and activator protein-1 DNA binding, while troglitazone inhibited these effects. The selective PPARγ antagonist GW9662 reversed MMP-9 inhibition by troglitazone in TPA-treated MCF-7 cells. CONCLUSION: Troglitazone inhibited nuclear factor κB and activator protein-1-mediated MMP-9 expression and invasion of MCF-7 cells through a PPARγ-dependent mechanism.

Characterization of Clostridium difficile Strains Isolated from Patients with C. difficile-associated Disease in Korea

OBJECTIVES: Studies on Clostridium difficile are rare in Korea. We investigated the epidemiological characteristics of C. difficile isolates from patients with C. difficile-associated disease (CDAD) in Korea. METHODS: Multiplex polymerase chain reaction was performed to detect the presence of tcdA and tcdB toxin genes. Antimicrobial susceptibility test was carried out by the disk-dilution method. C. difficile strains were subtyped by automated repetitive-element palindromic PCR (rep-PCR). RESULTS: Among patients with CDAD, 73 (25.8%), 32 (11.3%), 32 (11.3%), and 26 (9.2%) suffered from pneumonia, cancer or neoplasm, diabetes, and colitis, respectively. Of all stool samples, 43 samples (15.2%) were positive for C. difficile strains. We observed two expression patterns of toxin genes: tcdA+/tcdB+ (86% isolates) and tcdA−/tcdB+ (14% isolates), with all isolates expressing tcdB. Furthermore, some isolates were resistant to clindamycin (65%), ampicillin (56%), and cefazolin (40%), but all were susceptible to vancomycin and metronidazole. The tested samples were classified into diverse clusters using automated rep-PCR. CONCLUSION: Our findings revealed the characteristics and antibiotic resistance of C. difficile isolates from patients in Korea. The epidemiological data may provide valuable insight into development of treatment strategies for C. difficile infections in Korea.

Britanin Suppresses IgE/Ag-Induced Mast Cell Activation by Inhibiting the Syk Pathway

The aim of this study was to determine whether britanin, isolated from the flowers of Inula japonica (Inulae Flos), modulates the generation of allergic inflammatory mediators in activated mast cells. To understand the biological activity of britanin, the authors investigated its effects on the generation of prostaglandin D2 (PGD2), leukotriene C4 (LTC4), and degranulation in IgE/Ag-induced bone marrow-derived mast cells (BMMCs). Britanin dose dependently inhibited degranulation and the generations of PGD2 and LTC4 in BMMCs. Biochemical analyses of IgE/Ag-mediated signaling pathways demonstrated that britanin suppressed the phosphorylation of Syk kinase and multiple downstream signaling processes, including phospholipase Cgamma1 (PLCgamma1)-mediated calcium influx, the activation of mitogen-activated protein kinases (MAPKs; extracellular signal-regulated kinase 1/2, c-Jun NH2-terminal kinase and p38), and the nuclear factor-kappaB (NF-kappaB) pathway. Taken together, the findings of this study suggest britanin suppresses degranulation and eicosanoid generation by inhibiting the Syk-dependent pathway and britanin might be useful for the treatment of allergic inflammatory diseases.

Correlation of expression and activity of matrix metalloproteinase-9 and -2 in human gingival cells of periodontitis patients

PURPOSE: Matrix metalloproteinases (MMPs) are capable of degrading extracellular matrix, and they are inducible enzymes depending on an inflammatory environment such as periodontitis and bacterial infection in periodontal tissue. Gingival inflammation has been postulated to be correlated with the production of MMP-2 and MMP-9. The objective of this study was to quantify the expression and activity of MMP-9 and -2, and to determine the correlation between activity and expression of these MMPs in human gingival tissues with periodontitis. METHODS: The gingival tissues of 13 patients were homogenized in 500 microL of phosphate buffered saline with a protease inhibitor cocktail. The expression and activity of MMP-2 and -9 were measured by enzyme-linked immunosorbent assay and Western blot analysis, and quantified by a densitometer. For the correlation line, statistical analysis was performed using the Systat software package. RESULTS: MMP-9 was highly expressed in all gingival tissue samples, whereas MMP-2 was underexpressed compared with MMP-9. MMP-9 activity increased together with the MMP-9 expression level, with a positive correlation (r=0.793, P=0.01). The correlation was not observed in MMP-2. CONCLUSIONS: The expression of MMP-2 and -9 might contribute to periodontal physiological and pathological processes, and the degree of MMP-9 expression and activity are predictive indicators relevant to the progression of periodontitis.

Triptolide downregulates human GD3 synthase (hST8Sia I) gene expression in SK-MEL-2 human melanoma cells

In this study, we have shown that gene expression of human GD3 synthase (hST8Sia I) is suppressed by triptolide (TPL) in human melanoma SK-MEL-2 cells. To elucidate the mechanism underlying the downregulation of hST8Sia I gene expression in TPL-treated SK-MEL-2 cells, we characterized the TPL-inducible promoter region within the hST8Sia I gene using luciferase constructs carrying 5'-deletions of the hST8Sia I promoter. Functional analysis of the 5'-flanking region of the hST8Sia I gene demonstrated that the -1146 to -646 region, which contains putative binding sites for transcription factors c-Ets-1, CREB, AP-1 and NF-kappaB, functions as the TPL-inducible promoter of hST8Sia I in SK-MEL-2 cells. Site-directed mutagenesis and ChIP analysis indicated that the NF-kappaB binding site at -731 to -722 is crucial for TPL-induced suppression of hST8Sia I in SK-MEL-2 cells. This suggests that TPL induces down-regulation of hST8Sia I gene expression through NF-kappaB activation in human melanoma cells.

Role of IL-1 beta(Interleukin 1 beta) on Bone Resorption in Mouse Calvarial Bone / 대한정형외과연구학회지

PURPOSE: To determine the interactions between interleukin-1 beta(IL-1 beta) and bone cells in a fetal mouse bone model. MATERIALS AND METHODS: Fetal mouse calvarial bone cells were isolated and cultured. Alkaline phosphatase activity was measured by monitoring the release of p-nitrophenol from disodium p-nitrophenylphosphate. PGE2 was measured by radioimmunoassay and plasminogen activator activity was measured using [125 I]-fibrin coated multi-wells. The effects of systemic and local factors on bone resorption were assessed by measuring the percentage of 45 Ca release from prelabeled 19-day-old fetal mouse radii and ulnae by radioimmunoassay after 5 days culture. RESULTS: In this study, IL-1 beta stimulated cellular proliferation and the synthesis of prostaglandin E2 and plasminogen activator activity in the cultured cells in a dose-dependent manner. but alkaline phosphatase activity was decreased by IL-1 beta in a dose-dependent manner CONCLUSION: These studies support the role of IL-1 beta in the pathological modulation of bone cell metabolism, with regard to implication in the pathogenesis of osteoporosis by IL-1 beta.

Genome Mapping of an Extreme Thermophile, Thermus caldophilus GK24

Genome of an extreme thermophile, Thermus caldophilus GK24 has been analyzed to construct the genomic map. The genomic DNAs encapsulated in agarose gel were digested with SspI, EcoRI, SpeI, and HpaI restriction endonucleases, and then the resulting genomic DNA fragments were analyzed by pulsed-field gel electrophoresis. Its restriction map has been constructed by analyzing sizes of the restriction fragments obtained from both complete and partial digestions. The circular form of its genome was composed of about 1.98 Mbp and a megaplasmid. The genomic loci for the genes of xylose isomerase, thioredoxin, tRNA-16S rRNA, 23S rRNA, L5 ribosomal protein, ADP-glucose pyrophosphorylase, DNA-ligase, and Tca DNA polymerase were determined by both Southern hybridization and PCR.

Expression Patterns of PTEN (Phosphatase and Tensin Homologue Deleted on Chromosome 10) in Osteosarcoma / 대한정형외과학회잡지

PURPOSE: To characterize PTEN gene alterations and their expressions during the development of osteosarcoma. MATERIALS AND METHODS: We studied the pattern of deletion, mutation and expression of PTEN in normal bone tissues, tumor samples of 22 patients of osteosarcoma, and 4 osteosarcoma cell lines (HOS, U2-OS, MG-63 and Saos-2). The tissue was analyzed for deletion and mutational inactivation of PTEN by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and direct sequence analysis, and examined for abnormalities in expression by immunohistochemistry. RESULTS: In this study, neither mutation nor deletion of PTEN was found. Expression of PTEN protein was increased, without deletion or mutation of the PTEN gene, in 22 patients of osteosarcoma and in 4 osteosarcoma cell lines. Nuclear staining was more intense than the cytoplasmic staining in normal bone tissues and osteosarcoma cell lines, but in osteosarcoma tissues PTEN was expressed mainly in the cyto-plasm. CONCLUSION: These results suggest that abnormal expressions of PTEN by differential compartmentalization may play a role in the development and progression of osteosarcoma, instead of genetic alterations of PTEN.

Comparison of effect of interferon-alpha, lamivudine monotherapy and combination therapy in chronic hepatitis B / 대한내과학회지

BACKGROUND: Alpha-interferon achieves HBeAg seroconversion in about 30 to 40% of patients with chronic hepatitis B, and recently discovered lamivudine, an oral nucleoside analogue, inhibits hepatitis B virus replication and reduces hepatic necroinflammation in patients with chronic hepatitis B effectively. In this study, we compared the efficacy and safety of alpha-interferon, lamivudine and their combination regimen. METHODS: Fourty chronic hepatitis B patients, who were diagnosed through HBV DNA, HBeAg positivity, alanine aminotransferase elevation, and liver biopsy were enrolled in this study. Twelve patients were treated with 500 MU of alpha-interferon subcutaneously 3 times a week for 6 months, 9 patients were treated with 150 mg of lamivudine and alpha-interferon, and 19 patients were treated with 150 lamivudine daily for 6 months. RESULTS: After treatment, all of the three groups showed rapid decline in HBV DNA level, but lamivudine group showed more clearance of HBV DNA than interferon group (alpha-interferon: 75%, combination group: 89%, lamivudine group: 100%, respectively) (p=0.04). HBeAg seroconversion rate was 25% for interferon group, 11% for combination group, 26% for lamivudine group, showing no difference between three groups (p=0.705). Mean serum ALT level and rate of ALT normalization during therapy showed no differnece (83% for interferon group, 78% for combination group, 84% for lamivudine group). CONCLUSION: It is suggested that the efficacy of combination interferon/lamivudine therapy appears disappointing and further study should be done for appropriate combination or monotherapy of lamivudine for patients with chronic hepatitis B.

Effective Production and Clinical Application of Anti-Interleukin-6 Monoclonal Antibodies / 대한면역학회지

Highly specific and sensitive immunoassay method for soluble human recombinant interleukin-6 (hu rlL-6) was established by two different immunization methods. One is conventional method by Freund's adjuvant method and the other is special method which is directly injected to mouse spleen. Among seven established monoclonal antibodies (mAbs), two typical monoclonal antibodies, designated YB3 (IgG1) and NY2 (IgM), were further characterized. These mAbs highly bound to IL-6, however did not show cross reactivity with IL-1B and IL-2. As the results of ELISA inhibition assay and western blotting method, it was further identified that YB3 and NY2 had high binding specificity with IL-6. And the limiting detection amount of rlL-6 for YB3 was 5 ng/ml and for NY2 was 0.5 ng/ml. Furthermore, N-glycosylated human rlL-6 was also bound to YB3 on ELISA. On the other hand YB-3 furtherly recognized N-glycosylated human rlL-6 by sandwich ELISA method. These mAbs may be of use to diagnose the gynecopathy which contains abortion and preterm labor.

Effects of Pilose Antler on Lipid Peroxidation and Antioxidative Enzymes in Cultured Liver Cells / 대한면역학회지

No abstract available.