Cobalt ions induce chemokine secretion in a variety of systemic cell lines

Figures & data

Table 1. Cell cultures and culture medium used

Cell type	Medium	Passage no.
HK-2	DMEM/F12 (1:1), EGF, 10% FBS	12
AGS	Ham's F12, L-glutamine, 10% FBS	18
T-84	DMEM/F12 (1:1), L-glutamine, 10% FBS	24
SAE	Small Airway Medium with bullet kit (CC-3118, Cambrex, UK)	8
A-549	DMEM, 10% FBS	12
Neutrophils	RPMI medium 1640, 10% FBS	1
Monocytes	RPMI medium 1640, 10% FBS	1

DMEM: Dulbecco's modified Eagles medium; F12: nutrient mixture; EGF: epidermal growth factor; FBS: fetal bovine serum; RPMI: Roswell Park Memorial Institute.

Table 2. Apprixomate fold increase in chemokine secretion relative to contrtol levels

	Length of exposure of cell cultures
	4 hours		12 hours		24 hours		48 hours
Cell type	IL-8	MCP-1	IL-8	MCP-1	IL-8	MCP-1	IL-8	MCP-1
Renal epithelium	2	0	14 ^a	5 ^a	16 ^a	7 ^a	15 ^a	7 ^a
Gastric epithelium	2	1.2	2.5	2.5 ^a	3.7 ^a	3 ^a	4 ^a	3 ^a
Colonic epithelium	1.8	0	1.8	0	4 ^a	3.3 ^a	6 ^a	4 ^a
SAE	2.5	1.3	3	1.5	5 ^a	4 ^a	8 ^a	4 ^a
Alveolar epithelium	1.5	0	2	0	2	0	2	2
Neutrophils	0	2.5 ^a	2 ^a	4 ^a	2 ^a	4 ^a	N/A	N/A
Monocytes	1.5	1.6	2 ^a	3	2.5 ^a	4	2.5 ^a	6

^a p < 0.05

SAE: small airway epithelium; N/A: no available timpe point.

Figure 1. Cobalt ions (10ppm) induce enhanced secretion of IL-8 and MCP-1 chemokines in human renal tubular epithelial cells (HK-2) at 12, 24 and 48 h. Renal tubule epithelial cells were treated with 10 ppm cobalt ions for 4, 12, 24 and 48h along with a negative control. A: There is a significant increase in the secretion of IL-8 protein post exposure at 12, 24 and 48 h relative to the control sample (a = p < 0.001). B: There is also a significant increase in the secretion of MCP-1 protein at 12, 24, and 48h compared to negative control (a = p < 0.001).

Figure 2. Cobalt ions (10ppm) induce enhanced secretion of IL-8 and MCP-1 chemokines in human gastric epithelial cells (AGS). Gastric epithelial cells were treated with 10 ppm cobalt ions for 4, 12, 24 and 48h along with a negative control. A: There is a significant increase in the secretion of IL-8 protein post exposure at 24 and 48h relative to the control sample (a = p < 0.001). B: There is also a significant increase in the secretion of MCP-1 protein at 12, 24, and 48h compared to negative control (a = p < 0.001).

Figure 3. Cobalt ions (10ppm) induce enhanced secretion of IL-8 and MCP-1 chemokines in human colonic epithelial cells (T-84). Colonic epithelial cells were treated with 10 ppm cobalt ions for 4, 12, 24 and 48h along with a negative control. A: There is a significant increase in the secretion of IL-8 protein post exposure at 24 and 48h relative to the control sample (a = p < 0.001). B: There is also a significant increase in the secretion of MCP-1 protein at 24 and 48h compared to negative control (a = p < 0.001).

Figure 4. Cobalt ions (10ppm) induce enhanced secretion of IL-8 and MCP-1 chemokines in human small airway epithelial cells. Human small airway epithelial cells were treated with 10 ppm cobalt ions for 4, 12, 24 and 48h along with a negative control. A: There is a significant increase in the secretion of IL-8 protein post exposure at 24 and 48h relative to the control sample (a = p < 0.001). B: There is also a significant increase in the secretion of MCP-1 protein at 12, 24 and 48h compared to negative control (a = p < 0.001).