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  • IL-1β augments H2S-induced ...
    Ujike, Ayako; Kuraishi, Tomoki; Yamaguchi, Soichiro; Eguchi, Ryota; Kitano, Taisuke; Kamise, Jumpei; Ito, Shigeo; Otsuguro, Ken-ichi

    European journal of pharmacology, 02/2018, Volume: 821
    Journal Article

    H2S has excitatory and inhibitory effects on Ca2+ signals via transient receptor potential ankyrin 1 (TRPA1) and ATP-sensitive K+ channels, respectively. H2S converts intracellularly to polysulfides, which are more potent agonists for TRPA1 than H2S. Under inflammatory conditions, changes in the expression and activity of these H2S target channels and/or the conversion of H2S to polysulfides may modulate H2S effects. Effects of proinflammatory cytokines on H2S-induced Ca2+ signals and polysulfide production in RIN14B cells were examined using fluorescence imaging with fura-2 and SSP4, respectively. Na2S, a H2S donor, induced 1) the inhibition of spontaneous Ca2+ signals, 2) inhibition followed by Ca2+i increase, and 3) rapid Ca2+i increase without inhibition in 50% (23/46), 22% (10/46), and 17% (8/46) of cells tested, respectively. IL-1β augmented H2S-induced Ca2+i increases, which were inhibited by TRPA1 and voltage-dependent L-type Ca2+ channel blockers. However, IL-1β treatment did not affect Ca2+i increases evoked by a TRPA1 agonist or high concentration of KCl. Na2S increased intracellular polysulfide levels, which were enhanced by IL-1β treatment. A NOS inhibitor suppressed the increased polysulfide production and Ca2+i increase in IL-1β-treated cells. These results suggest that IL-1β augments H2S-induced Ca2+i increases via the conversion of H2S to polysulfides through NO synthesis, but not via changes in the activity and expression of target channels. Polysulfides may play an important role in the effects of H2S during inflammation.