Effect Of TIP30 Knock Out On Oval Cell-mediated Liver Regeneration

Objective:The liver is a complex and diverse organ.The normal function of the liver plays an important role in the survival of the body.When the liver is damaged due to chronic injury and the proliferation ability of the liver cells is inhibited,the function of proliferation and differentiation of hepatic oval cells will play an extremely important role in the process of liver regeneration.Chronic liver damage can also lead to liver fibrosis,and liver fibrosis may progress to cirrhosis and even liver cancer.Previous experiments in the research group showed that after liver damage was induced by DEN,the liver weight of the Tip30 knockout mice was significantly lower than the wild type,suggesting that liver regeneration was affected.Hepatic oval cells play an important role in the regeneration and repair of chronic liver injury,However,it has not been reported whether Tip30 affects regeneration and repair after hepatic injury by affecting the proliferation and differentiation of hepatic oval cells.The aim of this study was to elucidate the effect of Tip30 knockout on hepatic oval cell-mediated liver regeneration.Methods:1.The liver injury was induced by 3,5-diethyl-1,4-dihydrocollidine(DDC)in mice and measure the liver weight to understand the effect of Tip30 on liver regeneration and repair in mice;2.The liver injury was induced by DDC in mice.The effect of Tip30 on the proliferation of hepatic oval cells in mice was observed by immunofluorescence.3.The Tip30 of rat hepatic oval cells(WB-F344 cells)was silenced by siRNA and cell proliferation was detected by CCK8 assay.4.The Tip30 of rat hepatic oval cells(WB-F344 cells)was silenced by siRNA and the effect of migration by transwell.5.The hepatic oval cell differentiation was detected by RT-Q-PCR when Tip30 was silenced by siRNA;6.The changes of Wnt/β-catenin signaling pathway in liver of Tip30 knockout mice were detected by RT-Q-PCR and Western Blot.7.The expression of Notch1 in liver of Tip30 knockout mice were detected by RT-Q-PCR and Western Blot.8.The changes of Wnt/β-catenin signaling pathway in WB-F344 cells were detected by RT-Q-PCR and Western Blot,when Tip30 was silenced by siRNA.9.The expression of Notch1 in WB-F344 cells were detected by RT-Q-PCR,when Tip30 was silenced by siRNA.Results:1.After DDC treatment,the ratio of liver weight to body weight of Tip30 knockout mice was significantly decreased.2.After DDC treatment,the number of hepatic oval cells in Tip30 knockout mice was significantly lower;3.Down-regulation of Tip30 could inhibit the proliferation of hepatic oval cells(WB-F344);4.Down-regulation of Tip30 could inhibit the migration of WB-F344 cells.5.Down-regulation of Tip30 could promote the differentiation of hepatic oval cells into bile duct cells.6.After DDC treatment,the expression of Wnt/β-catenin was down-regulated in Tip30 knockout mice.7.After DDC treatment,the expression of Notch1 in liver of Tip30 knockout mice was up-regulated.8.Down-regulation of Tip30 could inhibit the expression of Wnt/β-catenin in WB-F344 cells.9.Down-regulation of Tip30 could promot the expression of Notch1 in WB-F344 cells.Conclusion:1.In vivo studies showed that after DDC treatment,the proliferation and migration of hepatic oval cells were inhibited in Tip30 knockout mice,resulting in decreased hepatic oval cells in the hepatic parenchyma of mice after hepatic injury,which in turn inhibited liver regeneration;2.In vitro studies showed that down-regulation of Tip30 expression could down-regulate the expression of β-catenin in WB-F344 cells,suggesting that down-regulation of Tip30 could inhibit the activation of Wnt/β-catenin signaling pathway,leading to decreased proliferation of hepatic oval cells and inhibited oval cell different into hepatocytes,which in turn inhibits liver regeneration.At the same time,the differentiation of hepatic oval cells into bile duct cells can be promoted by upregulating the expression of Notch1.