Effects of exogenous annexin-1 on lipopolysaccharide-induced proliferation and reactive oxygen species production partially through modulation of CRAC channels but independent of NF-kappaB pathway.

Abstract

To investigate the effects of exogenous annexin-1 (ANXA1) on lipopolysaccharide(LPS)-induced proliferation, reactive oxygen species (ROS) production, and calcium signal transduction in RAW264.7 macrophages. RAW264.7 macrophages were treated with or without LPS in the absence or presence of ANXA1. The proliferation effects were detected by Cell Counting Kit-8 assay. ROS were quantified by flow cytometry and fluorescence microscopy. Intracellular Ca(2+) concentration ([Ca(2+)](i)) was analyzed by laser confocal scanning microscopy. IkappaBalpha degradation and NF-kappaB translocation were tested by Western blot. Exogenous ANXA1 inhibited LPS-induced proliferation and ROS production in a dose-dependent manner. LPS evoked [Ca(2+)](i) increase through CRAC channels, and ANXA1 suppressed LPS-induced [Ca(2+)](i) increase in a dose-dependent manner. The CRAC channels were associated with LPS-induced proliferation and ROS production. Exogenous ANXA1 had no effect on LPS-induced IkappaB degradation and NF-kappaB translocation. ANXA1 inhibited LPS-induced proliferation and ROS production in RAW264.7 macrophages partially through modulation of CRAC channels but independent of the NF-kappaB pathway.