Lipid Supplement in the Cultural Condition Facilitates the Porcine iPSC Derivation through cAMP/PKA/CREB Signal Pathway

Large numbers of lipids exist in the porcine oocytes and early embryos and have the positive effects on their development, suggesting that the lipids may play an important role in pluripotency establishment and maintenance in pigs. However, the effects of lipids and their metabolites, such as fatty acids on reprogramming and the pluripotency gene expression of porcine-induced pluripotent stem cells (iPSCs), are unclear. Here, we generated the porcine iPSCs that resemble the mouse embryonic stem cells (ESCs) under lipid and fatty-acid-enriched cultural conditions (supplement of AlbuMAX). These porcine iPSCs show positive for the ESCs pluripotency markers and have the differentiation abilities to all three germ layers, and importantly, have the capability of aggregation into the inner cell mass (ICM) of porcine blastocysts. We further confirmed that lipid and fatty acid enriched condition can promote the cell proliferation and improve reprogramming efficiency by elevating cAMP levels. Interestingly, this lipids supplement promotes mesenchymal-epithelial transition (MET) through the cAMP/PKA/CREB signal pathway and upregulates the E-cadherin expression during porcine somatic cell reprogramming. The lipids supplement also makes a contribution to lipid droplets accumulation in the porcine iPSCs that resemble porcine preimplantation embryos. These findings may facilitate understanding of the lipid metabolism in porcine iPSCs and lay the foundation of bona fide porcine embryonic stem cell derivation.