LIF-Dependent, Pluripotent Stem Cells Established from Inner Cell Mass of Porcine Embryos

The pig is important for agriculture and as an animal model in human and veterinary medicine, yet, despite over 20 years of effort, it has proved a difficult species from which to generate pluripotent stem cells analogous to those derived from mouse embryos. Here we report the production of LIF-dependent, so called naïve type, pluripotent stem cells from the inner cell mass of porcine blastocysts by up-regulating expression of KLF4 and POU5F1. These cells resemble mouse ES cells and are distinct from the FGF2-dependent, induced pluripotent cell type derived from porcine somatic cells. Transcript profiling utilized Affymetrix porcine microarrays were conducted to compare the gene expressions associated with pluripotency in the two LIF-dependent pESK lines (pESK I & II, passage 14 & 5, respectively) with a naïve phenotype and two porcine iPSC lines (ID4 & ID6, both passage 7, GSE15472) with a primed phenotype that re-programming of porcine fetal fibroblasts (EGFP-PFF, GSE15472). The pESK lines clustered separately from the porcine iPSC lines, EGFP-PFF and primary cultures established from explants of porine umbilical cord (PUC). Porcine pluripotent stem cells were derived from the inner cell mass with transduction with human KLF4 by lentiviral transduction.