Leptin regulates STAT3 signalling and FTO expression in HuH-7 cells. HuH7 cells were transfecting with pcDNA3-LepRb and empty pcDNA3 vectors for 36 hours. Cells were then serum starved for 16 hours before leptin stimulation (100 ng/mL) during the indicated periods. A) Representative Western Blots of pSTAT3(Y705) and total STAT3, as well as FTO and actin proteins, in HuH-7 cells expressing LepRb treated with leptin (100 ng/mL). B-C) Quantitative analysis of both Y705 phosphorylation of STAT3 B) and FTO expression C) in 3-hour leptin treated transfected HuH7 cells, showing that B) leptin increases Y705 phosphorylation of STAT3 in LepRb expressing HuH7 cells, and that C) the overexpression of LepRb induces FTO protein levels. Data are means ± SEM (n = 6/group). *p < 0.05 compared to control transfected cells. LepRb: leptin receptor; STAT3: signal transducer and activator of transcription 3; FTO: fat-mass and obesity associated gene.