Oncostatin M maintains naïve pluripotency of mESCs by tetraploid embryo complementation (TEC) assay

It has been well established that (LIF) is essential for maintaining naive pluripotency of ESCs. Oncostatin M (OSM) is a member of the IL-6 family of cytokines which share gp130 as a receptor subunit, and the OSM-gp130 complex can recruit either LIF receptor β or OSM receptor β. Here we show that OSM can completely replace LIF to maintain naive pluripotency of mouse ESCs. Mouse ESCs cultured in the presence of LIF or OSM not only express pluripotency genes at similar levels but also exhibit the same developmental pluripotency as evidenced by generation of germline competent chimeras, supporting previous findings. Moreover, we demonstrate that mESCs cultured in OSM produce viable all-ESC pups by tetraploid embryo complementation (TEC) assay, the most stringent functional test of authentic pluripotency. Furthermore, the telomere length and telomerase activity also are crucial for unlimited self-renewal and genomic stability of mESCs, and these do not differ in mESCs cultured under OSM or LIF. The transcriptome of mESCs cultured in OSM overall is very similar to that of LIF, and OSM activates Stat3 signaling pathway, like LIF. Additionally, OSM upregulates pentose and glucuronate interconversions, ascorbate and aldarate metabolism, steroid and retinol metabolism pathways. Although the significance of these pathways remains to be determined, our data shows that OSM can maintain the naive pluripotent stem cells in the absence of LIF. Examination of gene expression profile of mouse ESCs in 3 different culture condition and each with two replicates.