Brefeldin A reduces tumor necrosis factor-α-stimulated production of inflammatory mediators by suppressing the Akt, mTOR, and NF-κB pathways in human keratinocytes

Keratinocytes may play an important role in the pathogenesis of inflammatory skin diseases. Brefeldin A has been shown to attenuate the production and secretion of chemical mediators involved in inflammation and immune responses. However, the effect of brefeldin A on the TNF-α-stimulated production of inflammatory mediators in keratinocytes has not been studied. We investigated the effect of brefeldin A on the TNF-α-stimulated production of inflammatory mediators using HaCaT cells and primary keratinocytes in relation to the Akt, mTOR, and NF-κB pathways, which regulates the transcription genes involved in immune and inflammatory responses. Brefeldin A, Akt inhibitor, Bay 11-7085 (an inhibitor of NF-κB activation), and rapamycin (mTOR inhibitor) inhibited the TNF-α-stimulated productions of inflammatory mediators, and activations of Akt, mTOR, and NF-κB in keratinocytes. The results show that brefeldin A appears to attenuate TNF-α-stimulated inflammatory mediator production in keratinocytes by suppressing the activation of the Akt, mTOR, and NF-κB pathways.