Upregulation of Oct-4 isoforms in pulmonary artery smooth muscle cells from patients with pulmonary arterial hypertension

Mol Physiol 298: L548–L557, 2010. First published February 5, 2010; doi:10.1152/ajplung.00314.2009.—Oct-4 is a transcription factor con-sidered to be one of the defining pluripotency markers in embryonic stem cells. Its expression has also been demonstrated in adult stem cells, tumorigenic cells, and, most recently and controversially, in somatic cells. Oct-4 pseudogenes also contribute to carcinogenesis. Oct-4 may be involved in the excessive proliferation of pulmonary arterial smooth muscle cells (PASMC) in patients with idiopathic pulmonary arterial hypertension (IPAH), contributing to the patho-genesis of IPAH. In this study, we show that Oct-4 isoforms are upregulated in IPAH-PASMC. Human embryonic stem cells (H9 line) and human PASMC from normotensive subjects were used through-out the investigation as positive and negative controls. In addition to significant upregulation of Oct-4 in a population of IPAH-PASMC, HIF-2, a hypoxia-inducible transcription factor that has been show