Leptin receptor long-form signalling in a human liver cell line

Expression of the long form of the leptin receptor was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting in the human liver cell line WRL68. Leptin (50-200 nM) significantly increased tyrosine phosphorylation of STAT cytoplasmic transcription factors STAT3 and STAT5b in a dose-dependent manner and produced a gel-shift with STAT3- and STAT5-specific oligonucleotides. WRL68 cells therefore provide the first human in vitro hepatocyte system in which to study leptin receptor-mediated signalling and to elucidate the role of leptin in liver.