OCT4 is a transcription factor that plays a crucial role in regulating pluripotency in embryonic stem cells. It was thought that OCT4 was epigenetically silenced in adult somatic cells; however, recent evidence suggests that OCT4 might be reactivated in some somatic cell types such as tumours. A recent study published in Nature Medicine suggests that OCT4 may play an atheroprotective role when it is activated in smooth muscle cells (SMC). After vascular injury or during the development of atherosclerosis smooth muscle cells are known to undergo dedifferentiation. This process is thought to cause the repair and remodeling of blood vessels after they have been damaged.
SMCs have increasingly been shown to be involved in this process and OCT4 is shown to be reactivated in SMCs following an atherosclerosis lesion. The researchers knocked out the OCT4 from SMC cells to test for its effects on lesion pathogenesis. They saw an increase in lesion size and a decrease in lesion stability after knocking out OCT4 from SMC cells. Comparisons with Klf4-knockout studies suggest that the loss of OCT4 affects the very early phases of lesion pathogenesis, which might disturb the migration of SMCs leading to a lesion that is without a fibrous cap and is therefore destabilized. The results therefore suggest that OCT4 plays an atheroprotective role in SMC. This study is one of the first that demonstrates a functional role of OCT4 and it also suggests that OCT4 might be functionally important in other somatic cells as well.
Summary Courtesy: Waleed Khan
Reference: Cherepanova, O. et al. Activation of the pluripotency factor OCT4 in smooth muscle cells is atheroprotective. Nat Med(2016). doi:10.1038/nm.4109