Administration of Protein Kinase D1 Induces a Protective Effect on Lipopolysaccharide-Induced Intestinal Inflammation in a Co-Culture Model of Intestinal Epithelial Caco-2 Cells and RAW264.7 Macrophage Cells

Figure 2

PKD1 stimulate secretion of TNF-α from LPS-stimulated RAW264.7 cells. Protein kinase D1 (PKD1; 0.001, 0.1, 10, 100 ng/ml) was administered apically to Caco-2 cells in co-culture with RAW264.7 cells. An inflammatory response was induced in RAW264.7 cells with 1 μg/ml lipopolysaccharide (LPS, E. coli: O127). Effects of PKD1 on secretion of TNF-α from RAW264.7 cells were evaluated in two different situations: (■) LPS was administered to RAW264.7 cells for 3 h, followed by PKD1 to Caco-2 cells for 3 h to investigate whether PKD1 can ameliorate an already induced inflammation. (□) PKD1 was administered to Caco-2 cells for 3 h at which point RAW264.7 cells were stimulated with LPS for 6 h to evaluate whether PKD1 can suppress inflammation initiation. TNF-α level in controls (no LPS stimulation) was undetectable (ND). Data are presented as means ± SEM (). Significant differences () within concentrations of PKD1 are indicated by the lowercase letters.