Establishment of a temperature-dependent cell line from rat endometrium by retroviral infection

We have established a cell line, RENTts3.1, by infection of primary rat endometrial cells with a retrovirus carrying a temperature-sensitive mutant of SV40 large T-antigen. These cells show a temperature-dependent phenotype with respect to morphology, growth and expression of macrophage colony-stimulating factor 1 (CSF-1) mRNA. At the permissive temperature, the cells grow with a doubling time of 24 h and exhibit an elongated, fibroblast-like morphology. They express vimentin and type III collagen mRNA. At the non-permissive temperature, the cells stop growing and exhibit an epitheloid morphology with flat enlarged cytoplasm. At the higher temperature, the cells continue to express type III collagen, but also express CSF-1 mRNA, and the cellular content of this transcript is influenced by glucocorticoid treatment. No expression of the epithelial markers cytokeratin, uteroglobin, beta-endorphin or preproenkephalin was detected, suggesting a stromal origin of the cell line. Electron microscopic data of cells cultivated on different substrates also support this conclusion. This cell line may be useful for the study of the molecular processes involved in decidual transformation of the endometrial mucosa.