Urocortin 1, urocortin 3/stresscopin, and corticotropin-releasing factor receptors in human adrenal and its disorders.
BACKGROUND
Urocortin 1 (Ucn1) and urocortin 3 (Ucn3)/stresscopin are new members of the corticotropin-releasing factor (CRF) neuropeptide family. Ucn1 binds to both CRF type 1 (CRF1) and type 2 receptors (CRF2), whereas Ucn3 is a specific agonist for CRF2. Recently, direct involvement of the locally synthesized CRF family in adrenocortical function has been proposed.


OBJECTIVE
We examined in situ expression of Ucn and CRF receptors in nonpathological human adrenal gland and its disorders using immunohistochemistry and mRNA in situ hybridization.


RESULTS
Ucn immunoreactivity was localized in the cortex and medulla of nonpathological adrenal glands. Ucn1 immunoreactivity was marked in the medulla, whereas Ucn3 was immunostained mostly in the cortex. Both CRF type 1 and CRF2 were expressed in the cortex, particularly in the zonae fasciculata and reticularis but very weakly or undetectably in the medulla. Immunohistochemistry in serial tissue sections with mirror images revealed that both Ucn3 and CRF2 were colocalized in more than 85% of the adrenocortical cells. mRNA in situ hybridization confirmed these findings above. In fetal adrenals, Ucn and CRF receptors were expressed in both fetal and definitive zones of the cortex. Ucn and CRF receptors were all expressed in the tumor cells of pheochromocytomas, adrenocortical adenomas, and carcinomas, but its positivity was less than that in nonpathological adrenal glands, suggesting that Ucn1, Ucn3, and CRF receptors were down-regulated in these adrenal neoplasms.


CONCLUSIONS
Ucn1, Ucn3, and CRF receptors are all expressed in human adrenal cortex and medulla and may play important roles in physiological adrenal functions.
Fukuda
Tsuyoshi
T
Department of Pathology, Tohoku University School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan. fukuda@patholo2.med.tohoku.ac.jp
Takahashi
Kazuhiro
K
Suzuki
Takashi
T
Saruta
Masayuki
M
Watanabe
Mika
M
Nakata
Taisuke
T
Sasano
Hironobu
H
D000236:Adenoma / Q000378:metabolism / Q000503:physiopathology; D000293:Adolescent; D000302:Adrenal Cortex / Q000502:physiology*; D000306:Adrenal Cortex Neoplasms / Q000378:metabolism / Q000503:physiopathology*; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003346:Corticotropin-Releasing Hormone / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007223:Infant; D007231:Infant, Newborn; D008875:Middle Aged; D010673:Pheochromocytoma / Q000378:metabolism / Q000503:physiopathology*; D012333:RNA, Messenger / Q000032:analysis; D018019:Receptors, Corticotropin-Releasing Hormone / Q000235:genetics* / Q000378:metabolism; D054832:Urocortins; D000099052:CRF Receptor, Type 1
C101531:CRF receptor type 2; D012333:RNA, Messenger; D018019:Receptors, Corticotropin-Releasing Hormone; C426704:UCN3 protein, human; D054832:Urocortins; D000099052:CRF Receptor, Type 1; D003346:Corticotropin-Releasing Hormone