Expression of the glucocorticoid receptor in the human adrenal cortex.
Glucocorticoids produced in the adrenal cortex act by binding to a specific intracellular protein, the glucocorticoid receptor (GR), which then modulates gene transcription in target tissues. Whether the adrenal cortex itself is a glucocorticoid target tissue has not been analyzed as yet. Since the presence of GR would be a prerequisite for such "intracortical" glucocorticoid action, this study was designed to analyze GR expression in the normal human adrenal gland using RT-PCR, Western blot, and immunohistochemistry. RT-PCR revealed the presence of GR mRNA in adrenal cortex as well as in NCIh295 cells. These results were confirmed at the protein level by Western blot employing a specific anti-human GR antibody. Immunohistochemically, weak GR staining was observed in the adrenal medulla. In contrast, GR was strongly expressed in the adrenal cortex with the zona reticularis showing the most intense staining. Transfection of a GR-responsive luciferase reporter gene into NCIh295 cells resulted in dexamethasone-dependent induction of luciferase activity, indicating that GR is functional in this tissue. In this study, we show for the first time that GR is expressed in the human adrenal cortex. Its preferential expression in the zona reticularis may indicate a functional role in the regulation of adrenal androgen biosynthesis.
Paust
H-J
HJ
Center of Internal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Loeper
S
S
Else
T
T
Bamberger
A-M
AM
Papadopoulos
G
G
Pankoke
D
D
Saeger
W
W
Bamberger
C M
CM
D000302:Adrenal Cortex / Q000502:physiology*; D002460:Cell Line; D006801:Humans; D007150:Immunohistochemistry; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D011965:Receptors, Glucocorticoid / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015385:Zona Reticularis / Q000502:physiology*
D012333:RNA, Messenger; D011965:Receptors, Glucocorticoid; C411470:glucocorticoid receptor alpha; C121943:glucocorticoid receptor beta