AIM:To investigate the molecular mechanisms involved in coagulation factor expression and/or function during direct hyperplasia(DH) -mediated liver regeneration.METHODS:Direct hyperplasia-mediated liver regeneration was induced in female C57BL/6 mice by administering 1,4-bis[2-(3,5-dichloropyridyloxy) ] benzene(TCPOBOP) ,a representative hepatomitogen.Mice were weighed and sacrificed at various time points [Day 0(D0:prior to injection) ,3 h,D1,D2,D3,and D10] after TCPOBOP administration to obtain liver and blood samples.Using the RNA samples extracted from the liver,a comprehensive analysis was performed on the hepatic gene expression profiling of coagulation-related factors by real-time RT-PCR(fibrinogen,prothrombin,factors Ⅴ,Ⅶ,Ⅷ,Ⅸ,Ⅹ,Ⅺ,Ⅻ,XⅢβ,plasminogen,antithrombin,protein C,protein S,ADAMTS13,and VWF) .The corresponding plasma levels of coagulation factors(fibrinogen,prothrombin,factors Ⅴ,Ⅶ,Ⅷ,Ⅸ,Ⅹ,Ⅺ,Ⅻ,XⅢ,and VWF) were also analyzed and compared with their mRNA levels.RESULTS:Gavage administration of TCPOBOP(3 mg/kg body weight) resulted in a marked and gradual increase in the weight of the mouse livers relative to the total body weight to 220% by D10 relative to the D0(control) ratios.At the peak of liver regeneration(D1 and D2) ,the gene expression levels for most of the coagulationrelated factors(fibrinogen,prothrombin,factors Ⅴ,Ⅶ,Ⅷ,Ⅸ,Ⅺ,Ⅻ,XⅢβ,plasminogen,antithrombin,protein C,ADAMTS13,VWF) were found to be downregulated in a time-dependent manner,and gradually recovered by D10 to the basal levels.Only mRNA levels of factor Ⅹ and protein S failed to show any decrease during the regenerative phase.As for the plasma levels,5 clotting factors(prothrombin,factors Ⅷ,Ⅸ,Ⅺ,and Ⅻ) demonstrated a significant decrease(P < 0.05) during the regeneration phase compared with D0.Among these 5 factors,factor Ⅸ and factor Ⅺ showed the most dramatic decline in their activities by about 50% at D2 compared to the basal levels,and these reductions in plasma activity for both factors were consistent with our RT-PCR findings.In contrast,the plasma activities of the other coagulation factors(fibrinogen,factors Ⅴ,Ⅶ,XⅢ,and VWF) were not significantly reduced,despite the reduction in the liver mRNA levels.Unlike the other factors,FX showed a temporal increase in its plasma activity,with significant increases(P < 0.05) detected at D1.CONCLUSION:Investigating the coagulation cascade protein profiles during liver regeneration by DH may help to better understand the basic biology of the liver under normal and pathological conditions. To investigate the molecular mechanisms involved in coagulation factor expression and / or function during direct hyperplasia (DH) -mediated liver regeneration. METHODS: Direct hyperplasia-mediated liver regeneration was induced in female C57BL / 6 mice by administering 1,4-bis [2- (3,5-dichloropyridyloxy) benzene (TCPOBOP), a representative hepatomitogen. Micr were weighed and sacrificed at various time points [Day 0 (D0: prior to injection), 3 h, D1, D2, D3, and D10] after TCPOBOP administration to obtain liver and blood samples. Using the RNA samples extracted from the liver, a comprehensive analysis was performed on the hepatic gene expression profiling of coagulation-related factors by real-time RT-PCR (fibrinogen, prothrombin, factors Ⅴ, Ⅶ, Ⅷ, Ⅸ, Ⅹ, Ⅺ, Ⅻ, XIIIβ, plasminogen, antithrombin, protein C, protein S, ADAMTS13, and VWF). The corresponding plasma levels of coagulation factors (fibrinogen, prothrombin, factors Ⅴ, , Ⅸ, Ⅹ, Ⅺ, Ⅻ, XIII, and VWF) were also analyzed and compared with t heir mRNA levels .RESULTS: Gavage administration of TCPOBOP (3 mg / kg body weight) resulted in a marked and gradual increase in the weight of the mouse livers relative to the total body weight to 220% by D10 relative to the D0 (control) the peak of liver regeneration (D1 and D2), the gene expression levels for most of the coagulation related factors (fibrinogen, prothrombin, factors Ⅴ, Ⅶ, Ⅷ, Ⅸ, Ⅺ, Ⅻ, XIIIβ, plasminogen, antithrombin, protein C , ADAMTS13, VWF) were found to be downregulated in a time-dependent manner, and more recently by D10 to the basal levels. Ony mRNA levels of factor X and protein S failed to show any decrease during the regenerative phase. As for the plasma The results showed that a significant decrease (P <0.05) during the regeneration phase compared with D0. Among these 5 factors, factor Ⅸ and factor Ⅺ showed the most dramatic decline (prothrombin, factors Ⅷ, Ⅸ, Ⅺ, in their activities by about 50% at D2 compared to the basal le vels, and these reductions in plasma activity for both factorswere consistent with our RT-PCR findings. Contrast, the plasma activities of the other coagulation factors (fibrinogen, factors Ⅴ, Ⅶ, XIII, and VWF) were not significantly reduced, despite the reduction in the liver mRNA levels .Unlike the other Factors, FX showed a temporal increase in its plasma activity, with significant increases (P <0.05) detected at D1.CONCLUSION: Investigating the coagulation cascade protein profiles during liver regeneration by DH may help to better understand the basic biology of the liver under normal and pathological conditions.