Hepatic gene expression during liver regeneration in response to partial hepatectomy: early time points (0.5h,1h,2h,4h)

The process of liver regeneration can be divided into a series of stages that include initial inductive or priming events through cellular mitosis. Following two-thirds liver resection, the liver undergoes the priming phase, in which cytokines TNF-a and IL-6 activate their respective receptors in hepatocytes. This leads to the activation of several key transcription factors: NF-kB, AP-1, Stat 3, Stat 1, and C/EBP-b and -d . These transcription factors induce the expression of immediate early genes. HGF is also expressed at this time and involved in the transition of quiescent hepatocytes into the G1 phase of the cell cycle. During the G1 phase, delayed early genes are expressed followed by induction of cell cyclerelated genes, both of which require new protein synthesis for their production. Increased expression of FoxM1B and TGF-a occurs at the G1/S transition and is correlated with increased expression of cyclinD1 and decreased expression of cdk inhibitors. During the G2/M phase of the cell cycle, FoxM1B directly elevates cyclinB1, cyclinB2, and cdc25B expression. Additionally, FoxM1B is associated with increased cyclinF and p55cdc, which are involved in completion of the cell cycle following partial hepatectomy. In mice, two-thirds partial hepatectomy promotes proliferation of liver cells and rapid growth of the remaining liver tissue, resulting in complete restoration of organ mass in approximately 7 days (Mackey S. et al. Hepatology 2003 Dec;38(6):1349-52).

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Singh P, Goode T, Dean A, Awad SS, Darlington GJ