Distribution pattern of somatostatin and cortistatin mRNA in human central and peripheral tissues.
BACKGROUND
Somatostatin receptors (sst) and their endogenous ligand, somatostatin (SS), are widely expressed throughout the human body. Recently, the cDNA of a novel SS-like peptide, named cortistatin (CST), has been cloned. This CST was found to be expressed in more restricted areas, like brain cortex, testes, kidney, stomach and leucocytes. Further studies demonstrated a selective expression of CST in tissues and cells of the human immune system, while SS was not expressed.


OBJECTIVE
In the present study we investigated the expression pattern of both SS mRNA and CST mRNA in various human central and peripheral tissues by quantitative RT-PCR (Q-PCR), in order to evaluate whether CST is more widely expressed in man than described to date and to investigate the relationship between SS and CST expression levels in various tissues. Previously, two different CST mRNA isoforms have been described. Therefore, we investigated the expression of both isoforms by RT-PCR in the different tissues as well.


RESULTS
We demonstrate for the first time that CST mRNA is widely expressed in the human body. Interestingly, a selective expression of CST mRNA and not SS mRNA was only found in isolated cells of the human immune system, whereas different tissues expressed both SS and CST mRNA.


CONCLUSIONS
CST may have a broader functional role than previously assumed.
Dalm
Virgil A S H
VA
Department of Internal Medicine, Josephine Nefkens Institute, Erasmus MC, Rotterdam, The Netherlands.
Van Hagen
P Martin
PM
de Krijger
Ronald R
RR
Kros
Johan M
JM
Van Koetsveld
Peter M
PM
Van Der Lely
Aart-Jan
AJ
Lamberts
Steven W J
SW
Hofland
Leo J
LJ
D006801:Humans; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013004:Somatostatin / Q000235:genetics / Q000378:metabolism*; D014018:Tissue Distribution
D009479:Neuropeptides; D020033:Protein Isoforms; D012333:RNA, Messenger; C099323:cortistatin; D013004:Somatostatin