Regulation of human amnion cell growth and morphology by sera, plasma, and growth factors

Inducing proliferation of human amnion epithelial and mesenchymal cells for prospective engineering of membrane repair

OBJECTIVE

To prepare a tissue engineering approach to fetal membrane repair after premature rupture of the membranes (PROM) by characterizing the proliferation potential of human amnion epithelial and mesenchymal cells from preterm and term placenta in primary culture.

METHODS

Amnion epithelial and mesenchymal cells from 15 preterm (23-36 week) and 27 term placentas collected at cesarean section were separated enzymatically, characterized immunohistochemically (anti-cytokeratin 18 and anti-E-cadherin, and anti-vimentin, respectively), and their ratio determined. Proliferation on tissue culture polystyrene (TCPS) or collagen in one medium and on TCPS in four different media after 14 days was measured photometrically and compared in preterm vs. term placenta. For statistical analysis the Mann-Whitney test was used.

RESULTS

Preterm and term epithelial:mesenchymal cell ratios were 4.3:1 and 7.8:1. Term epithelial cells proliferated similarly on TCPS or collagen. Mesenchymal cells proliferated only with fetal bovine serum (FBS). Proliferation of term amnion cells in medium containing FBS, epithelial growth factor (EGF), insulin, transferrin and triidothyronine(T3) was significantly increased (p < 0.001) compared with the other three media, and percentage proliferation was slightly higher in preterm cells.

CONCLUSION

Characterization of human amnion epithelial and mesenchymal cells identified the most potent proliferation-inducing medium yet. Studies of the wound-healing potential of these cells are needed, examining their behavior and proliferation on fibrin microbeads and other extracellular matrixes as the next step towards engineering membrane repair in PROM.

The low proliferation rates of human amniotic cells are neither associated to deregulated proto-oncogenes' expression nor to the effect of IFN alpha 2

Primary cultures of human amniotic membrane (PCHAM) cells display very low proliferation rates while their doubling times vary between 150 h and 210 h even after mitogenic stimuli. However, the pattern of proto-oncogenes (c-fos, c-myc and c-jun) expression in these cells, upon serum restimulation, resembled that of cell lines that display shorter population doubling times. Serum stimulation of quiescent PCHAM cells promoted a rapid and transient c-fos mRNA expression, which was detected within 10 min, reached maximal levels at 30 min and decreased to undetectable levels 2-3 h later. The levels of c-myc or c-jun mRNA increased within 10 min after serum restimulation, peaked at 3 h and decreased to intermediate levels thereafter. We also present evidence showing that IFN alpha 2 treatment of PCHAM cells had no effect on their population doubling times nor in c-fas, c-myc, or c-jun mRNA expression, under conditions in which induction of IFN-stimulated genes, such as 2'-5' oligo-adenylate synthetase (OAS) and 6-16 was observed. We conclude that the growth constraints observed with this cells are not directly associated with a negative cellular growth regulation exerted by IFN alpha 2, nor due to a deregulated proto-oncogenes' expression.

Catecholamines modulate epidermal growth factor-induced prostaglandin E2 production in amnion-like (WISH) cells by means of a cyclic adenosine monophosphate-dependent pathway

OBJECTIVE

The purpose of this study was to test the hypothesis that catecholamines can modulate epidermal growth factor-induced prostaglandin E2 production in amnion-derived cells via a cyclic adenosine monophosphate-dependent pathway.

STUDY DESIGN

Human amnion-derived WISH cells were used as the model system to study the regulation of prostaglandin E2 production. The concentrations of prostaglandin E2 and cyclic adenosine monophosphate were measured by radioimmunoassay. Statistical significance was determined with the Student t test.

RESULTS

Preexposure of WISH cells to either epinephrine, norepinephrine, or dopamine inhibited epidermal growth factor-induced prostaglandin E2 production. In addition, propranolol blocked both the increase in cyclic adenosine monophosphate accumulation and the inhibition of prostaglandin E2 production caused by epinephrine.

CONCLUSIONS

These results indicate that epidermal growth factor-induced prostaglandin E2 production can be attenuated by preexposure of amnion cells to catecholamines and that the inhibitory effect of catecholamines on epidermal growth factor response may be mediated via a beta-adrenergic receptor--coupled adenylate cyclase.

Human chorion cells respond to growth factors but lose steroidogenic capacity in primary monolayer cell culture

This study has defined a method for preparation and monolayer culture of cells from chorion laeve. Cell number and cell protein content are stable over 7 d in culture. The cells will divide in response to epidermal growth factor in the presence of a supplemented, enriched medium and a collagen matrix, but they lose steroidogenic activity over time in culture. This culture system can be used as the starting point for the development of a chemically defined hormone-supplemented, serum-free culture system for studies of chorion cell differentiation and fetal membrane cell interactions.