Neuropeptide urocortin 1 and its receptors are expressed in the human liver.
The corticotropin-releasing hormone (CRH) system, consisting of CRH, urocortins (Ucns), their receptors CRH(1) and CRH(2), and CRH-binding protein, holds the principal role in mediating the response to stress stimuli. Besides their expression in the brain, CRH neuropeptides and receptors have been found in multiple peripheral sites. We investigated the expression of the CRH system in the human liver, using RT-PCR and immunohistochemistry. Ucn 1 gene transcripts were amplified in all the human liver biopsies examined. Ucn 1 immunoreactivity was localized in hepatocytes. CRH(1) and CRH(2(alpha)) receptor gene expression was also found, and receptor protein had a similar distribution to Ucn 1. Finally, Ucn 1 and CRH receptor expression was demonstrated in hepatic biopsies from a variety of liver pathologies, including primary or metastatic liver carcinoma and cirrhosis. We conclude that the CRH system is expressed by human liver under normal and pathological conditions, Ucn 1 being the major ligand. Further study is required to unfold the biological role of these effectors in liver physiology and pathogenesis, as they may act in an autocrine manner through activation of the CRH receptors expressed locally.
Simopoulos
Constantinos
C
Second Department of Surgery, Democritus University of Thrace, Alexandroupolis, Greece.
Christodoulou
Eirini
E
Lambropoulou
Maria
M
Tsaroucha
Alexandra K
AK
Kakolyris
Stylianos
S
Polychronidis
Alexandros
A
Karayiannakis
Anastasios J
AJ
Chatzaki
Ekaterini
E
D002352:Carrier Proteins; D003346:Corticotropin-Releasing Hormone / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D022781:Hepatocytes / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D008099:Liver / Q000033:anatomy & histology / Q000378:metabolism*; D008107:Liver Diseases / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D018019:Receptors, Corticotropin-Releasing Hormone / Q000235:genetics / Q000378:metabolism*; D054832:Urocortins / Q000235:genetics / Q000378:metabolism*; D000099052:CRF Receptor, Type 1
C101531:CRF receptor type 2; D002352:Carrier Proteins; D012333:RNA, Messenger; D018019:Receptors, Corticotropin-Releasing Hormone; D054832:Urocortins; C067133:corticotropin releasing factor-binding protein; D000099052:CRF Receptor, Type 1; D003346:Corticotropin-Releasing Hormone