Effects of Oncostatin M on Invasion of Primary Trophoblasts under Normoxia and Hypoxia Conditions

Purpose: To investigate the effect of oncostatin M (OSM) on protein expression levels and enzymatic activities of matrix metalloprotainase(MMP)-2 and MMP-9 in primary trophoblasts and the invasiveness thereof under normoxia and hypoxia conditions. Materials and Methods: Protein expression levels and enzymatic activities of MMP-2 and MMP-9 in primary trophoblasts undernormoxia and hypoxia conditions were examined by Western blot and zymography, respectively. Effects of exogenous OSM onthe in vitro invasion activity of trophoblasts according to oxygen concentration were also determined. Signal transducer and activatorof transcription 3 (STAT3) siRNA was used to determine whether STAT3 activation in primary trophoblasts was involved inthe effect of OSM. Results: OSM enhanced protein expression levels and enzymatic activities of MMP-2 and MMP-9 in term trophoblasts under hypoxiacondition, compared to normoxia control (p<0.05). OSM-induced MMP-2 and MMP-9 enzymatic activities were significantlysuppressed by STAT3 siRNA silencing under normoxia and hypoxia conditions (p<0.05). Hypoxia alone or OSM alone didnot significantly increase the invasiveness of term trophoblasts. However, the invasion activity of term trophoblasts was significantlyincreased by OSM under hypoxia, compared to that without OSM treatment under normoxia. Conclusion: OSM might be involved in the invasiveness of extravillous trophoblasts under hypoxia conditions via increasingMMP-2 and MMP-9 enzymatic activities through STAT3 signaling. Increased MMP-9 activity by OSM seems to be more importantin primary trophoblasts.