Regulation of zonation and homeostasis in the adrenal cortex.
The adult adrenal cortex is organized into concentric zones, each specialized to produce distinct steroid hormones. Cellular composition of the cortex is highly dynamic and subject to diverse signaling controls. Cortical homeostasis and regeneration rely on centripetal migration of steroidogenic cells from the outer to the inner cortex, which is accompanied by direct conversion of zona glomerulosa (zG) into zona fasciculata (zF) cells. Given the important impact of tissue structure and growth on steroidogenic function, it is essential to understand the mechanisms governing adrenal zonation and homeostasis. Towards this end, we review the distinctions between each zone by highlighting their morphological and ultra-structural features, discuss key signaling pathways influencing zonal identity, and evaluate current evidence for long-term self-renewing stem cells in the adult cortex. Finally, we review data supporting zG-to-zF transdifferentiation/direct conversion as a major mechanism of adult cortical renewal.
Division of Endocrinology, Boston Children's Hospital, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA.
Emanuele
E
Pignatti
Division of Endocrinology, Boston Children's Hospital, Boston, MA 02115, USA; Division of Medical Sciences, Harvard Medical School, Boston, MA 02115, USA.
Sining
S
Leng
Division of Endocrinology, Boston Children's Hospital, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA; Harvard Stem Cell Institute, Cambridge, MA 02138, USA.
Diana L
DL
Carlone
Division of Endocrinology, Boston Children's Hospital, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA; Harvard Stem Cell Institute, Cambridge, MA 02138, USA. Electronic address: David.Breault@childrens.harvard.edu.
David T
DT
Breault
D000302:Adrenal Cortex / Q000033:anatomy & histology / Q000378:metabolism* / Q000648:ultrastructure; D000818:Animals; D000066673:Cell Self Renewal; D006706:Homeostasis; D006801:Humans; D008954:Models, Biological; D015398:Signal Transduction
ACTH; Adrenal cortex; Stem cell; Transdifferentiation; Wnt/β-catenin; Zonation