Sodium phenyl butyrate downregulates endothelin-1 expression in cultured human endothelial cells: relevance to sickle-cell disease.

As hydroxyurea (HU), sodium phenyl butyrate (SPB) is known to induce fetal hemoglobin (HbF) expression and thus shows potentials for sickle-cell disease (SCD) treatment. More recently, few studies suggested that endothelial cells (ECs), a major pathophysiological actor of SCD, are also a target of SPB. Here, we show that SPB, as HU, reduces endothelin-1 mRNA expression and peptide release by human ECs in culture. SPB increases VCAM-1 and ICAM-1 mRNAs and soluble ICAM-1 release. Both drugs have a cumulative effect on ICAM-1 expression. We conclude that SPB, as HU, also affects the expression of molecules important to the pathophysiology of SCD, in addition to its effect on HbF. Its potential as an alternative or adjuvant drug in SCD treatment warrants further investigations.