Cobalt ions induce chemokine secretion in a variety of systemic cell lines.
SourceUCD Clinical Research Centre, UCD School of Medicine and Medical Sciences, Mater Misericordiae University Hospital, Ireland. email@example.com
BACKGROUND AND PURPOSE:Metal ion toxicity both locally and systemically following MoM hip replacements remains a concern. Cobalt ions have been shown to induce secretion of proinflammatory chemokines locally; however, little is known about their effect systemically. We investigated the in vitro effect of cobalt ions on a variety of cell lines by measuring production of the proinflammatory chemokines IL-8 and MCP-1.
METHOD:Renal, gastrointestinal, and respiratory epithelium and also neutrophils and monocytes were exposed to cobalt ions at 4, 12, 24, and 48 hours.
RESULTS:We found that cobalt ions enhanced the secretion of IL-8 and MCP-1 in renal epithelial cells, gastric and colon epithelium, monocytes and neutrophils, and small airway epithelial cells but not in alveolar cells. Secretion of IL-8 and MCP-1 was markedly elevated in renal epithelium, where a 16-fold and 7-fold increase occurred compared to controls. There was a 6-fold and 4-fold increase in IL-8 and MCP-1 secretion in colon epithelium and a 4-fold and 3-fold increase in gastric epithelium. Small airway epithelial cells showed a maximum increase in secretion of 8-fold (IL-8) and of 4-fold (MCP-1). The increase in chemokine secretion observed in alveolar cells was moderate and did not reach statistical significance. Monocytes and neutrophils showed a 2.5-fold and 2-fold increase in IL-8 secretion and a 6-fold and 4-fold increase in MCP-1 secretion at 48 and 24 hours, respectively.
INTERPRETATION:These data demonstrate the potent bioactivity of cobalt ions in a variety of cell types and the potential to induce a proinflammatory response.
Chemokines (Greek -kinos, movement) are a family of small cytokines, or proteins secreted by cells. Their name is derived from their ability to induce directed chemotaxis in nearby responsive cells. Some chemokines are considered pro-inflammatory and can be induced during an immune response to recruit cells of the immune system to a site of infection, while others are considered homeostatic and are involved in controlling the migration of cells during normal processes of tissue maintenance or development