Effect of wild-type p53 gene on the number and proteins of centrosome in leukemic K562 cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To observe the effect of recombinant adenovirus-mediated wild-type p53 gene on the number and proteins of centrosome in K562 cells. To explore the possibility of application of wild-type p53 gene therapy in the treatment of chronic myeloid leukemia.</p><p><b>METHODS</b>The recombinant adenoviruses carrying wild-type p53 gene (Ad5 wtp53), mutant p53 gene (Ad5 mtp53) or the green fluorescent protein (GFP) gene was repeatedly amplified and co-infected into K562 cells with cation polybrene. The optimal infection titer and infection time of the recombinant adenoviruses were determined by MTT assay, p53 mRNA and protein expression were determined by RT-PCR and Western blot respectively. The centrosomal structural protein gamma-tubulin and the spindle protein alpha-tubulin were marked simultaneously by indirect immunofluorescence staining, and the expression of the centrosomal gamma-tubulin protein, the mitosis and the number of centrosome were observed under the laser confocal microscopy.</p><p><b>RESULTS</b>Infection efficiency with recombinant adenoviruses was facilitated by polybrene in K562 cells, and 4 microg/ml polybrene was chosen. The optimal adenovirus infection titer was 20,000 MOI and the optimal infection time was 72 hours. p53 mRNA and P53 protein can be expressed in K562 cells by Ad5wtp53 and Ad5mtp53. Both the expression of the centrosomal gamma-tubulin protein and the number of centrosomes were decreased after Ad5wtp53 infection.</p><p><b>CONCLUSION</b>There is sustained expression of P53 protein in K562 cells after its infection by Ad5wtp53. Wild-type P53 protein can lead to the down-regulation of the number of centrosomes and the expression of centrosomal gamma-tubulin protein in K562 cells.</p>

Methanol extract of Celastrus orbiculatu suppresses synovial hyperplasia and cartilage erosion and degradation in rheumatoid arthritis / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of methanol extract of Celastrus orbiculatu (MECO) on synovial hyperplasia and cartilage erosion and degradation in rheumatoid arthritis (RA), and explore the possible mechanisms to provide clues for new drug development for RA treatment.</p><p><b>METHODS</b>The articular synovium from patients with RA and normal articular cartilage were co-implanted into the back of severe combined immunodeficient (SCID)mice to establish the chimeric model SCID- HuRAg. Four weeks later, the mice were given MECO intragastrically at 30 mg/day, leflunomide at 500 microg/day or distilled water, respectively, for 4 consecutive weeks. After completion of the treatments, the histological scores of the grafts for synovial hyperplasia, cartilage invasion by synoviocyte and cartilage degradation around the chondrocytes were evaluated, and serum level of tumor necrosis factor-alpha (TNF-alpha) was measured with radioimmunoassay. The expression of TNF-alpha mRNA and the cell apoptosis in the synovium were detected with in situ hybridization (ISH) and TUNEL, respectively, and the results were analyzed with the image analysis system.</p><p><b>RESULTS</b>The grafts survived in the mice till the end of experiment. MECO and leflunomide, in comparison with distilled water, significantly lowered the scores for synovial hyperlasia (2.00+/-0.76 and 2.25+/-0.89 vs 3.63+/-0.52), cartilage erosion (1.69+/-0.80 and 2.00+/-1.36 vs 3.75+/-0.53), cartilage degradation (1.88+/-0.83 and 2.13+/-0.83 vs 3.63+/-0.74) and serum TNF-alpha level (0.84+/-0.09 and 0.83+/-0.12 vs 0.99+/-0.11 ng/ml). Cell apoptosis of the synovium increased significantly with MECO and leflunomide treatments, but the expression of TNF-alpha mRNA in the synovium decreased significantly in MECO group.</p><p><b>CONCLUSION</b>MECO can effectively suppress synovial hyperplasia and cartilage erosion and degradation SCID-HuRAg mice by reducing TNF-alpha production in the synovium and promoting synovial apoptosis. MECO can be comparable with leflunomide in their effect, but the former is more effective in suppressing TNF-alpha expression in the synovium.</p>