%0 Journal Article %T Comparison of Cell Viability and Embryoid Body Size of Two Embryonic Stem Cell Lines After Different Exposure Times to Bone Morphogenetic Protein 4 %J Iranian Journal of Medical Sciences %I Shiraz University of Medical Sciences %Z 0253-0716 %A Zarei Fard, Nehleh %A Talaei-Khozani, Tahereh %A Bahmanpour, Soghra %A Esmaeilpour, Tahereh %D 2015 %\ 03/01/2015 %V 40 %N 2 %P 110-117 %! Comparison of Cell Viability and Embryoid Body Size of Two Embryonic Stem Cell Lines After Different Exposure Times to Bone Morphogenetic Protein 4 %K Embryonic stem cells %K Bone morphogenetic protein 4 %K Embryoid body %R %X Background: Activation of bone morphogenetic protein 4 (BMP4) signaling pathway in embryonic stem (ES) cells plays an important role in controlling cell proliferation, differentiation, and apoptosis. Adverse effects of BMP4 occur in a time dependent manner; however, little is known about the effect of different time exposure of this growth factor on cell number in culture media. In this study, we investigated the role of two different exposure times to BMP4 in cell viability, embryoid body (EB), size, and cavitation of ES cells.Methods: Embryonic stem cells (R1 and B1 lines) were released from the feeder cell layers and were cultured using EBs protocol by using the hanging drop method and monolayer culture system. The cells were cultured for 5 days with 100 ng/mL BMP4 from the beginning (++BMP4) or after 48 h (+BMP4) of culture and their cell number were counted by trypan blue staining. The data were analyzed using non-parametric two-tailed Mann-Whitney test. P %U https://ijms.sums.ac.ir/article_39734_0a3439cee95e1fc2b17b112f606a0378.pdf