Effects of activin A on the pluripotency of induced pluripotent stem cells derived from porcine Sertoli cells

The Activin/Nodal signaling pathway is necessary for promoting the self-renewal and pluripotency in several species. However, these effects in porcine stem cells have yet to be examined. We hypothesized that Activin/Nodal signaling could be an important factor for maintenance of porcine induced pluripotent stem cells (iPSCs). The effects of activin A on pluripotency of porcine iPSCs derived from Sertoli cells were examined. Two iPS cell lines were cultured with different culture conditions (control, activin A, TGF-beta 1 inhibitor and activin A combined with TGF-beta 1 inhibitor). The Sertoli iPSCs treated with different conditions were compared for morphology, alkaline phosphatase (AP) activity, OCT4 protein expression and quantitative expression of genes (endogenous pluripotency genes and cell differentiated genes). This study revealed that the activin A treated iPSCs increased intensity of OCT4 protein expression. Furthermore, expressions of the pluripotent genes including OCT4 and NANOG were significantly upregulated in the activin A treated group (P < 0.05). In contrast, the selective TGF-beta 1 inhibitor adversely affected to iPSCs morphology and patterns of the AP and OCT4 protein expression. The TGF-beta 1 inhibitor also resulted in significant upregulation and downregulation for DES (mesoderm differentiation) and GATA 6 (endoderm differentiation), respectively (P < 0.05) when compared with other groups. In conclusion, activin A significantly upregulated the endogenous expression of OCT4 and NANOG pluripotent genes, thereby improving networks of the pluripotency in porcine iPSCs.