Figure 1.

Impacts of dietary cholesterol on various cells in the liver. (a) In hepatocytes, accumulated free cholesterol enhances the progression of fibrosis through various damages. LD, lipid droplet; ER, endoplasmic reticulum. (b) In Kupffer cells, oxidized LDL is internalized by SR-A and CD36 and then pro-inflammatory and pro-fibrogenic cytokines and chemokines are secreted. (c) In hepatic stellate cells, intracellular cholesterol stimulates the stellate cell activation, mainly due to the increased TLR4 receptor levels and elevated sensitivity to TGFβ. (d) In hepatic sinusoidal endothelial cells, increased free cholesterol (FC) in lysosomes attenuates the degradation of TLR9 and then activates the TLR9/inflammation pathway. LE, late endosome. Arrows: ↑, Increased; ↓, Decreased.