CC chemokine ligand 2 and LIF cooperatively promote pluripotency in mouse induced pluripotent cells

ABSTRACT: The pluripotency of mouse embryonic stem cells (ESC) and induced-pluripotent stem cells (iPSC) can be maintained by feeder cells, which secrete Leukemia Inhibitory Factor (LIF). We found that feeder cells provide a relatively low concentration (25 unit/ml) of LIF, which is insufficient to maintain the ESC/iPSC pluripotency in feeder free conditions. In order to identify additional factors involved in the maintenance of pluripotency, we carried out a global transcript expression profiling of mouse iPSC cultured on feeder cells and in feeder-free (LIF-treated) conditions. This identified 17 significantly differentially expressed genes (adjusted p-value<0.05) including 7 chemokines over-expressed in iPSC grown on feeder cells. Ectopic expression of these chemokines in iPSC revealed that CC chemokine ligand 2 (Ccl2) induced the key transcription factor genes for pluripotency, Klf4, Nanog, Sox2 and Tbx3. Further, addition of recombinant Ccl2 protein drastically increased the number of Nanog-GFP-positive iPSC grown in low LIF feeder free conditions. Interestingly, this effect was not observed in the absence of LIF. We further revealed that pluripotency promotion by Ccl2 is mediated by activating the Stat3-pathway followed by Klf4 up-regulation. We demonstrated that Ccl2 mediated increased pluripotency is independent of PI3K and MAPK pathways and that Tbx3 may be directly up-regulated by Klf4. Overall, Ccl2 cooperatively activates the Stat3-pathway with LIF in feeder free condition to maintain pluripotency for ESC/iPSC. Total RNAs were purified from feeder cells (as a reference sample), iPSC grown on feeder cells and iPSC grown in feeder-free condition in triplicates and applied to the arrays. iPSC grown on feeder cells were separated mechanically from the feeder layer to minimize feeder cell contamination.

ORGANISM(S): Mus musculus

SUBMITTER: Yuki Hasegawa 

PROVIDER: E-GEOD-28262 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress