Calcium influx blocked by SK&F 96365 modulates the LPS plus IFN-γ-induced inflammatory response in murine peritoneal macrophages

Abstract

A rise in intracellular Ca2+ ([Ca2+]i) is crucial for the activation of macrophages, however, the mechanisms and consequences of this [Ca2+]i increase remain unclear. This study investigated the role of calcium in mouse peritoneal macrophages stimulated with LPS plus IFN-γ by using the store-operated Ca2+ channel (SOCC) blocker SK&F 96365. Our results showed that SK&F 96365 pretreatment significantly inhibited the elevation of [Ca2+]i induced by ionomycin, thapsigargin, and LPS plus IFN-γ, respectively. Phagocytosis analyzing results showed that SK&F 96365 efficiently diminished the uptake of nonopsonized 1μM yellow-green beads or pHrodo™-labeled Escherichia coli bacteria both on the resting and LPS plus IFN-γ-stimulated macrophages. In addition, SK&F 96365 significantly inhibited the LPS plus IFN-γ-induced brisk uptake of NO and ROS. The CBA analyzing results showed that SK&F 96365 pretreatment efficiently inhibited the production of LPS plus IFN-γ-induced inflammatory cytokines of IL-6, MCP-1, TNF, INF-γ, and IL-10. However, SK&F 96365 pretreatment did not inhibit but augment the production of LPS plus IFN-γ-induced IL-1β secretion. Furthermore, SK&F 96365 pretreatment inhibited the LPS plus IFN-γ-induced translocation of NF-κB to the nucleus, and induced a decrease in mitochondrial membrane potential (ΔΨm) in LPS plus IFN-γ-activated macrophages. This study provides insight into the role of calcium in the activation of peritoneal macrophages induced by LPS plus IFN-γ, and blocking the calcium influx by SK&F 96365 exhibited a domain inhibitory effect on the LPS plus IFN-γ-induced inflammatory response in macrophages.