Figure 2.

(A) Regeneration. Platelets stimulate liver regeneration by three simultaneous interactions. (1) Kupffer cells: On binding platelets, Kupffer cells become activated and produce TNF‐α and IL‐6. (2) Hepatocytes: Platelets directly stimulate hepatocyte growth and proliferation through HGF, insulin‐like growth factor‐1, and VEGF. (3) Sinusoidal endothelial cells: Activated platelets produce sphingosine 1‐phosphate, which promotes liver regeneration through phosphorylation of Akt and extracellular signal‐regulated kinases 1/2. (B) Fibrosis. Platelets produce TGF‐β, PDGF‐β, and CXCL4 to aid conversion of hepatic stellate cells into collagen‐producing myofibroblasts. Abbreviations: ERK, extracellular signal‐regulated kinase; IGF‐1, insulin‐like growth factor 1; S‐1‐P, sphingosine 1‐phosphate.