ABSTRACT
Objective To investigate the role of Tmubl protein in liver cell proliferation. Methods Using silenced lentivirus (LV)-Tmubl vector, over-expression LV-Tmubl vector, and corresponding empty vectors to transfect rat’s liver cell line BRL-3A to obtain stable transfected cells, which bear the expression of Tmubl protein as detected by Western blotting, cell proliferation with MTT, and cell cycle with flow cytometry. Results The Tumbl protein expression in the hepatocytes transfected by LV-Tmubl was increased significantly and that by LV-Tmubl-RNAi decreased significantly, with a statistically significant difference compared with normal hepatocytes (P<0.01). The proliferation was fastest in hepatocytes transfected by LV-Tmubl and slowest in those by LV-Tmubl-RNAi, and the difference was statistically significant (P<0.01). The G2+S phase was longer in hepatocytes transfected by over-expression LV-Tmubl vectors than in those by silenced LV-Tmubl vectors, and the difference was statistically significant (P<0.01). Conclusion Tmubl protein can promote the hepatocyte proliferation in BRL-3A cell line.
ABSTRACT
Objective To investigate the interaction of Tmub1 and securin protein after partial hepatectomy. Methods A total of 30 adult male SD rats were randomly divided into 3 groups (10 each) according to the time after hepatectomy, i.e, 0, 24 and 48 h. Partial hepatectomy was performed in the rats in the first group, and then the primary hepatocytes were directly harvested by liver perfusion. Partial hepatectomy was also performed in the rest two groups at postoperative 24 and 48 h. Then the primary hepatocytes were also harvested respectively after liver perfusion. One part of primary hepatocytes was cultured for one night and for the observation of the colocalization of Tmub1 and securin protein with immunofluorescence. The other part of hepatocytes were used for co-immunoprecipitation and Western blotting to detect the expression of protein Tmub1/securin. Results Immunofluorescence and confocal laser scanning microscopy showed that there were almost no Tmub1 and securin proteins in the nucleus 0 h after liver resection, while a great amount of Tmub1/securin proteins were found to be co-localized in the nucleus 24 and 48 h. Co-immunoprecipitation and Western blotting showed that the expression of Tmub1/securing protein significantly enhanced in 24-48 h after operation compared with that at 0 h (P0.05). Conclusion Tmub1 hardly combines with securin protein in normal hepatocytes, but it combines with securin protein when it migrates from cytoplasm into nucleus after hepatectomy, thus inhibiting the proliferation process of hepatocytes.