Expression of leptin and leptin receptor isoforms in the human stomach.
BACKGROUND
Leptin is an important regulator of food intake and energy expenditure. Initially it was thought to be expressed exclusively in and secreted by adipocytes. Recently, leptin expression was also noted in other tissues, including rat gastric mucosa. Information on leptin and leptin receptor expression in the human stomach is lacking.


OBJECTIVE
To investigate expression of leptin and its corresponding receptors in human gastric epithelial cells.


METHODS
Fundic and antral gastric mucosal biopsies, primary cultures of human gastric epithelial cells, and the human gastric cancer cell line AGS were screened for expression of leptin and different leptin receptor isoform mRNA by reverse transcriptase-polymerase chain reaction. Immunohistochemistry was performed for localisation of leptin and leptin receptor proteins in gastric mucosa.


RESULTS
mRNA of leptin and its four receptor isoforms (huOB-R, long receptor isoform; huB219.1-3, short receptor isoforms) was detected in gastric mucosal biopsies, cultured human gastric epithelial cells, and gastric cancer cells. Immunohistochemistry demonstrated that chief as well as parietal cells were reactive to leptin and leptin receptors.


CONCLUSIONS
Leptin and leptin receptors are expressed in human gastric mucosa. These findings suggest a paracrine and/or autocrine effect of leptin on gastric epithelial cell function.
Mix
H
H
Department of Gastroenterology and Hepatology, Medizinische Hochschule Hannover, Germany.
Widjaja
A
A
Jandl
O
O
Cornberg
M
M
Kaul
A
A
Göke
M
M
Beil
W
W
Kuske
M
M
Brabant
G
G
Manns
M P
MP
Wagner
S
S
D001706:Biopsy; D002352:Carrier Proteins / Q000378:metabolism*; D002478:Cells, Cultured; D005753:Gastric Mucosa / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D020738:Leptin / Q000235:genetics / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000378:metabolism; D014407:Tumor Cells, Cultured
D002352:Carrier Proteins; C515448:LEPR protein, human; D020738:Leptin; D020033:Protein Isoforms; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin