Evidence for the involvement of endothelial cell products in adrenal CITED2 expression

Endothelial cells regulate β-catenin activity in adrenocortical cells via secretion of basic fibroblast growth factor

Endothelial cell-derived products influence the synthesis of aldosterone and cortisol in human adrenocortical cells by modulating proteins such as steroidogenic acute-regulatory (StAR) protein, steroidogenic factor (SF)-1 and CITED2. However, the potential endothelial cell-derived factors that mediate this effect are still unknown. The current study was perfomed to look into the control of β-catenin activity by endothelial cell-derived factors and to identify a mechanism by which they affect β-catenin activity in adrenocortical NCIH295R cells. Using reporter gene assays and Western blotting, we found that endothelial cell-conditioned medium (ECCM) led to nuclear translocation of β-catenin and an increase in β-catenin-dependent transcription that could be blocked by U0126, an inhibitor of the mitogen-activated protein kinase pathway. Furthermore, we found that a receptor tyrosin kinase (RTK) was involved in ECCM-induced β-catenin-dependent transcription. Through selective inhibition of RTK using Su5402, it was shown that receptors responding to basic fibroblast growth factor (bFGF) mediate the action of ECCM. Adrenocortical cells treated with bFGF showed a significant greater level of bFGF mRNA. In addition, HUVECs secrete bFGF in a density-dependent manner. In conclusion, the data suggest that endothelial cells regulate β-catenin activity in adrenocortical cells also via secretion of basic fibroblast growth factor.

Moving toward personalized cell-based interventions for adrenal cortical disorders: part 1--Adrenal development and function, and roles of transcription factors and signaling proteins

Transdifferentiation of an individual's own cells into functional differentiated cells to replace an organ's lost function would be a personalized approach to therapeutics. In this two part series, we will describe the progress toward establishing functional transdifferentiated adrenal cortical cells. In this article (Part 1), we describe adrenal development and function, and discuss genes involved in these processess and selected for use in our pilot studies of transdifferentiation that are presented in the second article (Part 2).