Progesterone and 17β‐estradiol increase differentiation of mouse embryonic stem cells to motor neurons

Abstract

Abstract Embryonic stem (ES) cells have the capacity to differentiate into endodermal, mesodermal, and ectodermal lineages. Motor neuron (MN) differentiation of mouse ES cells involves embryoid bodies formation with addition of Sonic hedgehog and retinoic acid. In this work, using immunocytochemistry, flow cytometry, and quantitative RT‐PCR, we investigated whether progesterone or 17β‐estradiol have inductive effects on ES cell‐derived MN, as it has been demonstrated that these hormones modify proliferation and neural differentiation of pluripotent cells. When 100 nM progesterone was added during differentiation, we found higher proportions of MN, compared to the control condition; coincubation of progesterone with the progesterone receptor (PR) antagonist RU‐486 caused a decrease in the number of MN to a percentage even lower than controls. The addition of nanomolar concentrations of 17β‐estradiol also significantly induced MN differentiation. This effect of estradiol was completely antagonized by addition of the general estrogen receptor (ER) antagonist ICI 182,780. To identify the ER subtype mediating the increase on MN differentiation, we incubated estradiol with the ER‐α antagonist MPP or with the ER‐β blocker PHTPP. When we coincubated 17β‐estradiol with MPP, we found a significant decrease in the percentage of MN. In contrast, the coincubation of 17β‐estradiol with PHTPP had no effect on the induction of MN differentiation. All these effects on cell number were confirmed by significant changes in the expression of the MN markers Islet‐1 and Choline acetyl transferase, assessed by real‐time RT‐PCR. Cell proliferation in embryoid bodies was significantly enhanced by progesterone treatment. No changes in apoptotic cell death were found in differentiating cells after progesterone or 17β‐estradiol addition. Our findings indicate that progesterone and 17β‐estradiol induce a higher proportion of MN derived from mouse ES cells through intracellular PR and ER, respectively. Furthermore, the effect of estradiol was mediated by specific activation of ER‐α. © 2011 IUBMB IUBMB Life, 2011