Effects of leukemia inhibitory factor on transcript expression of pluripotent genes in bovine embryonic stem like cells

Leukemia inhibitory factor (Lif) is very important for embryonic stem cell establishment. In this study, we investigated effects of Lif on transcript expression of pluripotent genes of bovine embryonic stem like cells in passage 1, passage 3 and passage 6. The results showed that Lif supplementation of medium could improve transcript expression of pluripotent gene including nanog, oct4, sox2 and c-myc. Three Lif concentrations were applied for cell culture medium. We found that pluripotent gene transcripts were highest expressed in 103 IU/ml Lif supplemented medium, especially nanog and oct4 transcript expression could be maintained until 6th passage . The transcript expression was decreased in 104 IU/ml Lif suppmented medium, suggesting that high concentration of Lif could inhibit pluripotent gene expression. Thus, 103 IU/ml Lif was the most efficient concentration to improve transcript expression of pluripotent genes. There was a relationship in nanog expression and c-myc and sox2 expression. C-myc and sox2 expression were up-regulated when nanog was down-regulated. We also accessed nanog or oct4 which were key factors for the maintenace of pluripotency and renewal of bovine embryonic stem like cell. The result demonstrated that nanog could be the key factor for pluripotency of bovine embryonic stem like cells.