Thymic stromal lymphopoietin is regulated by the intracellular calcium

The cytokine thymic stromal lymphopoietin (TSLP) has been implicated in the development and progression of allergic diseases such as atopic dermatitis. However, it has not been clarified that TSLP would be regulated by intracellular calcium in mast cells yet. To determine it, we blocked intracellular calcium by treatment with calcium chelator, 2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester (BAPTA-AM) in human mast cell line (HMC-1) cells. BAPTA-AM inhibited the production and mRNA expression of TSLP in phorbol myristate acetate plus A23187- stimulated HMC-1 cells. BAPTA-AM also inhibited the nuclear factor-κB activation, IκBα phosphorylation, receptor interacting protein2 (RIP2) expression, and caspase-1 activation in HMC-1 cells. These results provide evidence that calcium regulates the level of TSLP through RIP2/caspase-1/NF-κB/IκBα signal.