The effect of a Rho kinase inhibitor Y-27632 on superoxide production, aggregation and adhesion in human polymorphonuclear leukocytes

Abstract

We investigated the involvement of p160ROCK (a Rho-associated coiled coil-forming protein kinase), one of Rho kinases on superoxide anion production (O 2 − production), aggregation and adhesion of human polymorphonuclear leukocytes under physiological condition, using a selective p160ROCK inhibitor, (+)-( R)- trans-4-(1-aminoethyl)- N-(4-pyridyl)cyclohexanecarboxamide (Y-27632). Y-27632 inhibited the O 2 − production stimulated by phorbol-12-myristate-13-acetate (PMA) in a dose-dependent manner. Stauroprorine blocked the PMA-induced O 2 − production while wortmannin did not. Y-27632 also inhibited the O 2 − production by guanosine 5′- O-(3-thiotriphosphate) (GTP γS) 100 μM. N-formyl-Met-Leu-Phe (fMLP)-induced O 2 − production was not influenced by Y-27632, but was inhibited by wortmannin. The enhanced O 2 − production by Ca-ionophore A23817 and thapsigargin was not inhibited by Y-27632. Y-27632 did not change the basal intracellular Ca 2+ concentration nor its elevation stimulated by fMLP. Polymorphonuclear leukocytes aggregation induced by PMA was dose-dependently decreased by Y-27632 while their aggregation stimulated by fMLP was enhanced by the agent. Polymorphonuclear leukocytes adhesion induced by PMA or fMLP was not influenced by Y-27632. These results suggest that p160ROCK is involved in the PMA-induced O 2 − production and aggregation in human polymorphonuclear leukocytes. This kinase might locate in downstream of protein kinase C in polymorphonuclear leukocytes.