Leptin reduces the inhibitory effect of cvtokines and enhances SOC-1 gene expression in differentiated mammary cells

Leptin receptors has been shown to be expressed in several tissues, suggesting that this protein might be peripherally effective in metabolic and hormonal functions. In this study we report a specific relationship among leptin, prolactin (PRL) and interleukin 6 (IL-6) and tumor necrosis-alpha (TNF-alpha) in modulation of the suppressor of cytokine signaling 1 (SOCS-1). Also, we show as leptin and PRL are able to effectively enhance SOCS-1 gene expression in HC11 cell line. High concentrations of leptin (100 nM) and/or PRL significantly (p < 0.05) reduce the inhibitory effect of IL-6 (10 and 100 ng/ml) and TNF-alpha (10 and 100 ng/ml) on beta-casein gene expression in HC11 cells. These results provide evidence that leptin may be an important mediator in regulating mammary gland growth and this role may be related to the immune factors involved in inflammation.