Ak. Brar et al., LAMININ DECREASES PRL AND IGFBP-1 EXPRESSION DURING IN-VITRO DECIDUALIZATION OF HUMAN ENDOMETRIAL STROMAL CELLS, Journal of cellular physiology, 163(1), 1995, pp. 30-37
The expression of laminin, a major constituent of endometrial cell bas
ement membranes, is increased during differentiation of human endometr
ial stromal cells (decidualization). To determine whether laminin play
s a role in decidualization, we studied the effects of laminin substra
te on the synthesis and release of prolactin (PRL) and insulin-like gr
owth factor binding protein-1 (IGFBP-1), two major secretory proteins
of decidualized stromal cells. Endometrial stromal cells were plated o
n laminin as well as several other extracellular matrix (ECM) proteins
(types 1 and IV collagen or fibronectin) and on plastic, and cultured
in media containing medroxyprogesterone acetate (MPA) and estradiol.
Cells cultured on plastic or ECM proteins displayed similar morphologi
cal changes indicative of decidualization. However, the release of PRL
and IGFBP-1 from cells cultured on plastic and ECM proteins (types 1
and IV collagen and fibronection) was approximately 2.1-fold and 2.8-f
old greater respectively, than from cells cultured on laminin. The dec
rease in PRL and IGFBP-1 expression in cells cultured on laminin was n
ot due to differences in initial cell attachment efficiency or final D
NA content. In addition, laminin had no effect on the content of lamin
in protein or fibronectin mRNA levels, indicating that the effects of
laminin on PRL and IGFBP-1 were specific. PGE(2) stimulated the releas
e of PRL and IGFBP-1 from cells cultured on laminin to levels comparab
le to those from cells cultured on plastic or other ECM proteins. This
indicates that the decrease in PRL and IGFBP-1 release by laminin was
not due to a generalized unresponsiveness. In contrast to the effects
of laminin during decidualization, PRL expression was not altered by
laminin in terminally differentiated decidual cells isolated at term.
Our results support a role for laminin in selectively regulating PRL a
nd IGFBP-1 gene expression during in vitro decidualization of human en
dometrial stromal cells. (C) 1995 Wiley-Liss, Inc.