Define role of Leptin in controlling gene expression?

Leptin is a protein product (containing 167 amino acids) of the ob gene expressed exclusively in the adipose tissue. This protein molecule functions as an afferent signal in a negative feedback loop, centred in the hypothalamus, regulating the size of the adipose tissue mass.Leptin has been shown to modulate the synthesis of neuropeptides, particularly Neuropeptide Y (NPY) that regulates food intake. Increases energy expenditure as indicated by animal experiments. Leptin induced weight loss is completely specific for adipose tissue. While feeding does not appear to modulate leptin expression, fasting acutely decreases plasma leptin concentration. In general, obese humans have high leptin levels and the available data suggest that human obesity is likely to be associated with insensitivity to leptin.