Expression of Notch/Jagged signaling during liver regeneration after partial hepatectomy in rat

Abstract

Objective To study the effects of Notch/Jagged signaling pathway, TNF-α and IL-6 on liver regeneration after partial hepatectomy(PH). Methods The lever tissue was kept for 0 min,5 min,15 min, 30 min, 1 h, 3 h, 6 h, 12 h, 1 d, 2 d, 4 d, 7 d after PH to observe it. Immunohisto-chemistry and RT-PCR were used to study the expression of Notch-1 and Jagged-1 protein and mR-NA. Results After PH, staining of Notch-1 protein was enhanced in sinusoidal endothelia and peri-portal hepatoeytes. Enhanced staining for Jagged-1 protein was observed in bile duct and periportal hepatocytes. Notch-1 mRNA was down-regulated between 6 h and 2 d after partial hepateetomy. Jag-ged-1 mRNA was up-regulated between 3 h and 6 h, down-regulated between 12 h and 2 d, and recov-ered at 4 d. The expression of PCNA increases in 12 h after PH and reached its peak in 1-2 d. Serum density of IL-6 and TNF reached its peak in 24 h and 3 h, respectively. Conclusion Notch/Jagged signaling pathway plays an important role during liver regeneration after PH. It can promote bile duct formation and sustain the construction, contributing to the new small vessel formation and hepatocytes proliferation. TNF-α can activate the expression of IL-6, but IL-6 participates in the whole processes. Key words: Liver regeneration; Notch-1; Jagged-1