Morphology of luminal and glandular epithelial cells from pig endometrium grown on plastic or extracellular matrices

Luminal (LE) and glandular epithelial (GE) cells from d-13 pregnant pigs were cultured on plastic, matrix secreted from endometrial stroma, and EHS matrix (Matrigel) in culture medium (RPMI-1640) supplemented with 20 and 10% fetal bovine serum, respectively. After culture for 7 and 14 d, GE and LE cells were prepared for transmission and GE cells for scanning electron microscopy. The two types of endometrial epithelial cells displayed different morphological characteristics when grown on different culture substrates. On plastic, the GE and LE cells formed flattened monolayers. However, stroma-secreted matrix directed the polarization of endometrial epithelia. The GE and LE cells reacted differently to thick Matrigel coatings; LE cells formed a colony after 7 d of culture and then proliferated further to form a colony with a cavity, but GE cells organized to form a colony with a shallow depression in the center at 7 d and developed duct-like structures after 14 d in vitro. Luminal epithelial cells grown on either diluted or thin-coated Matrigel and grown on stroma-secreted matrix formed a monolayer but no three-dimensional structures.