Hydrogen peroxide upregulates interleukin-1β-induced cyclooxygenase-2 expression in human pulmonary epithelial cells

Objective To investigate th e effect of hydrogen peroxide(H 2O 2) on interleukin-1β(IL-1β)-induced cy clooxygenase-2(COX-2) expression in human pulmonary epithelial cells(HPEC) Methods HPEC were stimulated by IL-1β or H 2O 2 or both of them, COX-2 mRNA expression was determined by reverse transcription-polymerase chain reaction(RT-PCR), and prostaglandin E 2( PGE 2) release was detected by enzyme-linked immunosorbent assay(ELISA) Ce lls that were not stimulated by any reagent were used as controls Results (1) The relative amount of COX-2 mRNA expression induced by 1,5 and 10 mg/L of IL-1β [(143 1±7 2)%, (179 9±9 0)%, (190 0±9 5)%, respectively] was significantly higher than that in the control group (32 9±1 7)% (P0 05, respectively) (2) The concentration of PGE 2 released by HPEC treated with 5 and 10 mg/L of IL-1β[(20 86±5 23)×10~ -6 g/L, (31 16±2 64)×10~ -6 g/L, respectively] was significantly higher than that in the control group(10 49±0 36)×10~ -6 g/L(P0 05, respectively) (3) The relative amount of COX-2 mRNA expression induced by 0 10, 0 25 and 0 50 mmol/L of H 2O 2 in the presence of IL-1β[(149 2±7 5)%, (189 6±9 5)%, (239 1±12 0)%, respectively] was significantly higher than that in the cells treated with IL-1β alone (66 1±3 7)% or that in the control group (41 6±2 1)%(P0 05, respectively) (4)The concentration of PGE 2 released by HPEC treated with 0 10, 0 25 and 0 50 mmol/L of H 2O 2 in the presence of IL-1β [( 27 01±5 16)×10~ -6 g/L, (32 79±3 01)×10~ -6 g/L, (41 13±3 41)×10~ -6 g/L, respectively] was significantly higher than that in the control group (10 49±0 36) ×10~ -6 g/L (P0 05, respectively) The concentration of PGE 2 released by cells treated with 0 25 or 0 50 mmol/L of H 2O 2 in the presence of IL-1β was significantly higher than that in the cells treated with IL-1β alone (20.86±5.23) ×10~ -6 g/L (P0 05, respectively). Conclusion Hydrogen peroxid e upregulates IL-1β-induced COX-2 expression in HPEC at transcriptional level