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ABSTRACT: Interleukin-8 (IL-8) mRNA was constitutively expressed in human hepatoma cell line, HepG2 and in human hepatocellular carcinoma (HCC), which often form hypervascular tumors. The sequence 5'-AGGAAG-3' at -137 to -132 bp of IL-8 promoter was shown to be polyomavirus enhancer A binding protein-3 (PEA3) binding site, which can cooperate with activator protein-1 (AP-1). Both PEA3 and AP-1 are essential for constitutive IL-8 expression in HepG2 cells, determined by promoter assays. Moreover, PEA3 and IL-8 proteins coexisted in HCC tissues, but not in uninvolved liver tissues. It is possible PEA3 may have important roles in tumor progression and in angiogenesis in HCC.
Biochemical and Biophysical Research Communications 01/2001; 279(1):166-71. · 2.48 Impact Factor
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ABSTRACT: To investigate the molecular mechanisms of muscle atrophy under microgravity, the paraspinal muscles of rats after 14 days spaceflight and those of ground-based controls were examined. In the microgravitational environment, expressions of 42 genes changed, and the expressions of heat shock protein 70 and t complex polypeptide 1 increased. In Northern blotting, myocyte-specific enhancer binding factor 2C (MEF2C) and MEF2C-related genes including aldolase A and muscle ankyrin decreased. After 9 days ground recovery, expression of MEF2C increased and it was located mainly on the satellite cells in the muscle regeneration state. MEF2C could be a key transcriptional factor for skeletal muscle atrophy and regeneration under microgravity.
FEBS Letters 08/2000; 477(1-2):135-40. · 3.54 Impact Factor
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ABSTRACT: To identify rheumatoid arthritis (RA) specific autoantibody and its antigen in the human osteoblast-like cell line, MG-63.
MG-63 cell extract was subjected to western blotting by using RA and normal serum samples as probes. The autoantigen was purified and its N-terminal sequence was determined by automated Edman degradation. The reactivity of denatured aldolase A was evaluated by immunoblotting. Screening by enzyme linked immunosorbent assay (ELISA) using the autoantibody was performed.
40 kDa protein was found only in the RA serum samples and it was identified as aldolase A. A polyclonal antibody for rabbit muscle aldolase A bound to the 40 kDa protein and reacted in preference with the denatured enzyme. Using ELISA for denatured rabbit aldolase A, the autoantibody was found in approximately 10% of RA patients, whereas it was not found in the other arthropathy and healthy adults.
This 40 kDa anti-aldolase A autoantibody, which was identified only in serum samples of RA patients with severe bone erosion, could be related to a certain event that induces RA specific joint destructions.
Annals of the Rheumatic Diseases 04/1999; 58(3):169-74. · 8.73 Impact Factor
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ABSTRACT: To clarify the mechanism of thrombin receptor mediated signal transduction and the induction of cytokines by thrombin stimulation in rheumatoid synovial fibroblasts.
Cytokines were measured by enzyme linked immunosorbent assay (ELISA) in the supernatants of cultured rheumatoid synovial fibroblasts stimulated by thrombin. To assess the mechanism of thrombin receptor mediated signal transduction in the rheumatoid synovial fibroblasts, electrophoretic mobility gel shift assay (EMSA), immunoglobulin kappa-chloramphenicol acetyltransferase (CAT) assay, and immunostaining for NF-kappa B subunit molecule was performed.
Thrombin stimulation activated the inducible transcription factor NF-kappa B, and then induced subsequent expressions of interleukin 6 (IL6) and granulocyte colony stimulating factor (G-CSF) in the cells.
Thrombin receptor mediated signal transduction could induce the expressions of IL6 and G-CSF, and increase inflammatory events in the cavum articulare via NF-kappa B activation.
Annals of the Rheumatic Diseases 02/1999; 58(1):55-60. · 8.73 Impact Factor
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ABSTRACT: To develop gene therapy for patients with human T cell leukemia virus type I (HTLV-I)-associated arthropathy (HAAP), we investigated the effects of ribozyme-mediated cleavage of HTLV-I tax/rex messenger RNA (mRNA) on synovial overgrowth.
We introduced 2 hammerhead ribozymes targeted against HTLV-I tax/rex mRNA into synovial cells obtained from patients with HAAP and from patients with HTLV-I-negative rheumatoid arthritis (RA) and examined the ribozyme-mediated ablation of Tax expression. Using standard methods, we also determined the cells' ability to stop proliferating and to undergo apoptosis.
The ribozymes successfully cleaved tax/rex mRNA in HAAP patient synoviocytes. Both tax mRNA expression and Tax protein synthesis were inhibited significantly, resulting in inhibition of synovial cell growth and induction of apoptosis. In contrast, synovial cells from RA patients were not affected.
In vitro results suggest that ribozyme-mediated gene therapy can inhibit the growth of HTLV-I-infected synovial cells, which is maintained by Tax protein, in HTLV-I-related diseases including HAAP.
Arthritis & Rheumatism 01/1998; 40(12):2118-27. · 7.87 Impact Factor
