Influence of Hypoxic Condition on Invasion of Cultured Trophoblast

Baik, Ean Jeong; Shin, Jong Chul; Jung, Dae Young; Yang, Dong Eun; Kim, Jae Dong; Rho, Seung Hye; Lee, Jong Seung; Kim, Sa Jin; Kim, Chang Ie; Kim, Soo Pyung

Abstract

OBJECTIVE
To investigated whether lowering oxygen tension affects invasion of cultured trophoblast.
METHODS
Trophoblasts were isolated from the normal placenta in early pregnancy(6-10 weeks in gestation). Isolated trophoblasts were cultured under normoxic(5% CO2, 95% humid air in incubator) and hypoxic(MERCK, 1% O2, 99% CO2) conditions for 24, 48 and 72 hours, respectively. The proliferation ability was measured using [H3] thymidine assay. Total RNA was extracted from the cultured trophoblasts. The expressions of matrix metalloproteinase(MMP-2) and tissue inhibitor of metallo- proteinase(TIMP-2) were determined by reverse transcription- polymerase chain reaction(RT-PCR) and Northern blot analysis. The invasiveness of cultured trophoblast was observed using in vitro invasion assay.
RESULTS
[H] thymidine assay indicated that cellular DNA synthesis was not affected by the culture condition. The expression of MMP-2 mRNA was decreased at 24 hours and then progressively increased in the time-dependent manner in each culture condition. The expression of TIMP-2 was decreased in the time-dependent manner under hypoxic condition. In vitro invasion assay revealed that the cultured trophoblasts under hypoxic condition has more invasive ability than them under normoxic condition.
CONCLUSION
These data suggests that hypoxic condition may stimulates the invasion of trophoblast in the human placentation. And MMP-2 and TIMP-2 may be related to control their invasiveness under hypoxic condition.