Quantitative analysis of cellular morphology duringin vitrodecidualization

Decidualization is a differentiation process involving shape reorganization from a fibroblast to an epithelioid-like appearance of endometrial stromal cells. Specificities of these cells impede the use of existing automated tools to follow morphological changes during differentiation; we therefore developed a simple but accurate methodology to quantify the phenotypical changes that occur in an in vitro decidualization system. The approach consists of the analysis of the circularity of the cells directly from light microscopy images. Here, we used this methodology to follow the effects of progesterone or progestin R5020 in combination with estradiol (E2) and cAMP on inducing the decidualization of human endometrial cells. We further implemented a statistical model to detect the differences in the kinetics of decidualization of the two hormonal stimuli before all the cell population acquired the decidual phenotype. We found that 2 days after stimulation are sufficient to detect statistical differences in morphology between decidualization induced and control cells. Here, we detail the model and scripts in order to provide a useful, practical and low cost tool to evaluate morphological aspects of endometrial stromal differentiation. Availability and implementation See supplementary methods Supplementary information Supplementary data is available online.