YKL-40 expression in CD14+ liver cells in acute and chronic injury

Figure 1 YKL-40 mRNA expression in whole liver tissue samples with acute and chronic injuries induced by CCl4. After acute injury, YKL-40 mRNA increased in a gradual and constant pattern and then fell to control levels. The maximum 26-fold increase was reached at 24 h in the acute damage model. For the chronic injury model, at 6 and 8 wk, YKL-40 mRNA levels were increased 7- and 9-fold compared to controls, respectively. ^aP≤ 0.05. REU: Relative expression units.

Figure 2 YKL-40 protein levels show a gradual increase. The maximum peak was at 72 h in the acute damage model and 6 wk in the chronic injury model, with 2.01 and 6.35-fold increases, respectively. ^bP≤ 0.05 respect to the control group. REU: Relative expression units.

Figure 3 YKL-40 protein expression in cellular populations isolated from liver tissue. A: In healthy livers, expression of YKL-40 protein was lower in CD14⁺ and CD14^- subpopulations. B: In cells from livers exposed to acute damage, YKL-40 protein levels were higher in CD14⁺ cells. C: In the chronic injury model, hepatocytes showed low levels of YKL-40, with significant difference between CD14⁺ and CD14^- cells against hepatocytes (^cP < 0.05). REU: Relative expression units.

Figure 4 YKL-40 mRNA expression was induced by lipopolysaccharide in cell culture. After 3 and 12 h of stimulation with lipopolysaccharide, YKL-40 mRNA levels were increased by 9- and 11-fold, respectively, in a rat alveolar macrophage cell line (^dP < 0.05). Unstimulated cells were used as controls. REU: Relative expression units. LPS: Lipopolysaccharide.