Endocrine Abstracts

Wnt proteins are morphogens that are involved in morphogenesis, differentiation and stem cell biology in a variety of tissues. In the adrenal cortex, WNT4 is expressed at a higher level in the zona glomerulosa (ZG) and mice deficient in WNT4 have a defect in this zone. In this laboratory we confirmed that WNT4 is expressed at a higher level in the human ZG and showed that this is accompanied by higher expression of a potential antagonist, dickkopf-3 (DKK3). To investigate the role of these Wnt molecules we made adenoviruses expressing these proteins and used them to infect cultures of human and bovine adrenocortical cells. There were profound effects on levels of steroidogenic enzyme mRNAs, including a stimulation of CYP11B2, a key ZG enzyme. These data suggest that Wnt signalling has a major role in adrencortical cell differentiation.