Figure 7.

Schematic of the cellular mechanisms used by resolvin E1 (RvE1) and resolvin D1 (RvD1) to block leukotriene B4 (LTB4)–stimulated increase in intracellular [Ca²⁺] ([Ca²⁺]_i) and mucin secretion in cultured conjunctival goblet cells. A: RvE1 blocks the effect of LTB4 on both intracellular Ca²⁺ and secretion by either interacting with the LTB4 receptor BLT1 receptor or by activating the β-adrenergic receptor kinase (BARK1) that phosphorylates BLT1, causing its internalization. B: RvD1 only blocks the effect of LTB4 on increasing intracellular Ca²⁺, but not on secretion, because RvD1 does not interact directly with the BLT1 receptor, but only activates the BARK1 that phosphorylates BLT1 causing its internalization. In this case, LTB4 interacts with the BLT1 receptor to release intracellular Ca²⁺ and stimulate secretion. ALX/FPR, lipoxin A4 receptor/formyl peptide receptor; CMKLR1, chemerin chemokine-like receptor; IP3, inositol trisphosphate.