Spheroid Formation of Bovine Endometrial Stromal Cells with Non-Adherent Culture Plate.

Abstract

A multicellular mass (spheroid) was developed from bovine endometrial stromal cells with non-adherent culture plates. Cells cultured in a spheroid-plate® were spontaneously aggregated and formed a cell mass rough in appearance 24 h after the start of culture. After 3 days of culture, the cell mass became oval-shaped in the range 375 to 900 μm in diameter. The size of the spheroid depended on the number of cells plated in each well. Histological examination indicated that each spheroid was covered with a single layer of squamous cells, and cuboidal cells occupied the inside of the spheroid. The size of the spheroid decreased gradually and the inner cells of the spheroid became sparse and irregular in size after culture for more than 7 days. ProMMP-2 mRNA was found both in monolayer culture cells and the spheroid, but the active form of MMP-2 protein was found only in the condition medium of the spheroid. The present study demonstrated that the spheroid was easily generated from bovine endometrial stromal cells by using a non-adherent plate. Expression of the active form MMP-2 indicates that the cells in the spheroid changed their character not only morphologically but also functionally. These results indicate that the spheroid developed by the present method could provide a new tool for analyzing the functions of bovine endometrium.