RESUMO
Objective To investigate the effects of methylprednisolone pulse therapy on the expression of phosphorylated signal transducer and activator of transcription 1 (STATI) and DNA-binding activity of STATI in T cells in patients with severe systemic lupus erythematosus (SLE). Methods Six patients were included. Patients were given 0.5～1 g of methylprednisolone on 3 consecutive days. Western Blotting was conducted to explore the phosphorylated STATI expression and electrophoretic mobility shift assays (EMSA) were carried out to detect the DNA-biding activity of STATI. Results Methylprednisolone pulse therapy decreased phosphorylated STATI expression of T cells from patients with severe SLE. The expression of phosphorylated STATI decreased to about 30% 72 h after the methylprednisolone pulse therapy started (t=2.858, P<0.05). Methylprednisolone pulse therapy down-regulated DNA-biding activity of STATI of T cells in patients with severe SLE. The STATI DNA-biding activity was inhibited to about 40% 72 h after methy-Iprednisolone pulse, therapy started (t=3.058, P<0.05). Conclusion Phosphorylated STATI expression and DNA-binding activity of T cells is markedly decreased in patients after methylprednisolone pulse therapy, suggesting that inhibition of STATI signaling contributes to the clinical efficacy of this agent.