Transgenic expression of Ad4BP/SF-1 in fetal adrenal progenitor cells leads to ectopic adrenal formation.
Deficiency of adrenal 4 binding protein/steroidogenic factor 1 (Ad4BP/SF-1; NR5A1) impairs adrenal development in a dose-dependent manner, whereas overexpression of Ad4BP/SF-1 is associated with adrenocortical tumorigenesis. Despite its essential roles in adrenal development, the mechanism(s) by which Ad4BP/SF-1 regulates this process remain incompletely understood. We previously identified a fetal adrenal enhancer (FAdE) that stimulates Ad4BP/SF-1 expression in the fetal adrenal gland by a two-step mechanism in which homeobox proteins initiate Ad4BP/SF-1 expression, which then maintains FAdE activity in an autoregulatory loop. In the present study, we examined the effect of transgenic expression of Ad4BP/SF-1 controlled by FAdE on adrenal development. When Ad4BP/SF-1 was overexpressed using a FAdE-Ad4BP/SF-1 transgene, FAdE activity expanded outside of its normal field, resulting in increased adrenal size and the formation of ectopic adrenal tissue in the thorax. The increased size of the adrenal gland did not result from a corresponding increase in cell proliferation, suggesting rather that the increased levels of Ad4BP/SF-1 may divert uncommitted precursors to the steroidogenic lineage. The effects of FAdE-controlled Ad4BP/SF-1 overexpression in mice provide a novel model of ectopic adrenal formation that further supports the critical role of Ad4BP/SF-1 in the determination of steroidogenic cell fate in vivo.
Zubair
Mohamad
M
National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki 444-8787, Japan.
Oka
Sanae
S
Parker
Keith L
KL
Morohashi
Ken-Ichirou
K
D000302:Adrenal Cortex / Q000378:metabolism / Q000473:pathology; D000311:Adrenal Glands / Q000196:embryology* / Q000378:metabolism / Q000473:pathology*; D000375:Aging / Q000473:pathology; D000818:Animals; D049109:Cell Proliferation; D002828:Choristoma / Q000378:metabolism* / Q000473:pathology; D004742:Enhancer Elements, Genetic / Q000235:genetics; D005333:Fetus / Q000166:cytology*; D018507:Gene Expression Regulation, Developmental; D051379:Mice; D008822:Mice, Transgenic; D013234:Stem Cells / Q000378:metabolism* / Q000473:pathology; D054339:Steroidogenic Factor 1 / Q000235:genetics* / Q000378:metabolism; D013909:Thorax / Q000473:pathology; D019076:Transgenes / Q000235:genetics; D014566:Urogenital System / Q000196:embryology / Q000473:pathology; D001616:beta-Galactosidase / Q000378:metabolism
D054339:Steroidogenic Factor 1; D001616:beta-Galactosidase