Thrombin-induced chemokine production in endometrial stromal cells

BACKGROUND: In order to investigate the regulation of chemokines [interleukin-8 (IL-8), growth-regulated oncogene (GRO)α, monocyte chemoattractant protein-1 (MCP-1)) induced by thrombin in endometrial stromal cells (ESCs), the effects of thrombin, a protease activated receptor (PAR)-1 antagonist (PPACK), mitogen-activated protein kinase kinase inhibitor (U0126), phospholipase C inhibitor (U-73122), an antagonist of the intracellular InsP3 receptor (2-aminoethoxy-diphenylborate (2-APB)] and a protein kinase C inhibitor (GF-109203X) on the production of chemokines by ESCs were evaluated. METHODS: ESCs from eight endometrial specimens in the secretory phase were cultured and incubated for 24h with thrombin and PPACK, U0126, U-73122, 2-APB or GF-109203X. The levels of IL-8, GROα and MCP-1 in the culture medium were measured by means of ELISA. The activation of MAP kinase was detected by western blot analysis using anti-phosphorylated MAP kinase (ERK1/2) antibody. RESULTS: Following stimulation by thrombin, the production of IL-8, GROα and MCP-1 increased significantly in a dose-dependent manner. PPACK, U0126, U-73122, 2-APB or GF-109203X suppressed the increases in production of IL-8, GROα and MCP-1 induced by thrombin (P < 0.001, P <0.001 and P <0.001, respectively). MAP kinase activities were induced by treatment with thrombin, and were suppressed by PPACK, U0126, U-73122, 2-APB or GF-109203X. CONCLUSIONS: Our results suggest that thrombin stimulates the production of IL-8, GROα and MCP-1 via PAR-1 by a mechanism involving the MAP kinase system. The increases in IL-8, GROα and MCP-1 may contribute to the maintenance of implantation involving leukocyte chemotaxis.