OBJECTIVETo explore the role of stem cell mobilization on regeneration of partially grafted livers.

METHODSRats models with cross-sex 50% PLTx (partial liver transplantation) were established. The rats were divided into three groups: PLTx, WLTx (whole liver transplantation) and sham operation groups. Bone marrow and liver samples were collected on days 1, 3, 5, 7 postoperatively (each n = 6). The quantitative variations of the cells with stem cell markers in the bone marrow, including beta2m-/Thy-1.1+, CD45+/CD34+, Flt2/3+ and c-kit+ markers, were detected using flow cytometry. Sry gene positive cells in donor livers were detected by fluorescent in situ hybridization (FISH), and the expressions of CD34, c-kit and Thy-1.1 were detected by immunohistochemistry technique.

RESULTSCompared with the WLTx and sham operation groups, beta2m-/Thy-1.1+, CD45+/CD34+ cells in bone marrows in the PLTx group increased on the first postoperative day and decreased on the following days. The CD34, c-kit and Thy-1.1 positive cells detected in portal tract areas peaked during the 3-5 postoperative days. CD34+/CD45+ positive cells could be detected. The expressions of CD34, c-kit and Thy-1.1 positive cells were rare in the WLTx and sham operation groups. Sry+ cells could be detected in portal tract areas and few Sry+/CD34+ and Sry+/Thy-1.1+cells were detected.

CONCLUSIONIn the PLTx group, the stem cells in the bone marrow were mobilized and stem cells in the liver were activated.