Figure 2.

The role of Kupffer cells and HSCs in progression of ALD. In ALD patients, high levels of circulating LPS bind to TLR4 and activate Kupffer cells in liver. A large amount of ROS and pro-inflammatory cytokines (TNF-α, TGF-β, IL-1 and IL-6) are generated and released. When received oxidative and inflammatory stimulation, quiescent HSCs transform into activated HSCs, resulting in HSCs self-proliferation and fibrogenesis. HSC, hepatic stellate cell; ALD, alcoholic liver disease; LPS, lipopolysaccharide; TLR4, toll-like receptor type 4; ROS, reactive oxygen species; IL, interleukin.