Submitted June 30, 2005
Returned for revision July 19, 2005
Accepted August 26, 2005
Pregnancy
Difference in Progesterone Receptor Isoforms Ratio,
Between Early and Late First Trimester Human Trophoblast,
Is Associated with Differential Cell Invasion and Matrix
Metalloproteinase2 (MMP2) Expression
Shlomit Goldman
and
Eliezer Shalev *
* To whom correspondence should be addressed. E-mail: shaleve{at}tx.technion.ac.il.
Abstract
The expression profile of the progesterone receptor
isoforms and progesterone regulation
of MMP2 were investigated in early and late first
trimester trophoblast cells.
Human trophoblast cells were obtained from legal abortions
(6 to 12 weeks). Purity of
95-98% was verified using immunohistochemistry with
specific antibodies. Evaluation of
cell count was performed with XTT Reagent kit and invasion
was tested using Matrigel
invasion assay. Zymography was used to detect proteolytic
activity and Western blot was
used to study protein concentration. Gene expression of
PGRB, PGR and MMP2 was
studied using reverse transcription-polymerase chain
reaction with the housekeeping gene
GAPDH used for normalization. Promoter activity was
determined using Luciferase
reporter Assay. Differential progesterone receptor profile
was documented with the
dominance of PGRB in early trophoblast and dominance of
PGRA in late trophoblast.
This differential profile is compatible with the inverse
effect of the progesterone on the
two cell populations decreasing invasion and gelatinase
expression in the early first
trimester trophoblast and increasing invasion and
gelatinase expression in the late first
trimester trophoblast. A decrease in MMP2 promoter
activity in early trophoblast cells
exposed to progesterone suggests that MMP2
expression is regulated by progesterone at
the transcriptional level as well. Early trophoblast cells
transfected with expressing vector
for PGR encoding PGRA revealed less MMP2 activity
and reversal of its response to
progesterone similar to the effect observed in late
trophoblast cells.
Key words:
Mechanisms of Hormone Action •
Gene regulation •
Progesterone receptor •
Steroid hormone receptors •
Syncytiotrophoblast
