Objective: To explore the recurring patterns of migration and distribution of transplanted bone marrow stromal cells (BMSCs) in rat model with hepatic fibrosis and the feasibility of magnetic resonance (MR) tracing.
Methods: BMSCs labeled with 5-bromodeoxyuridine (Brdu) and super para-magnetic iron oxide (SPIO) were transplanted into rat model with hepatic fibrosis via portal vein. MR scan was performed at Hour 2, Day 3, Day 7 and Week 2 post-transplantation to analyze the hepatic features of MR signal intensity and pathohistology of BMSCs.
Results: Multiple hypo-intense lesions appeared in hepatic hilar region at Hour 2 and became smaller with the elapsing time. Hemosiderin and Brdu immunohistochemical stains showed that positive cells were found in portal vein of hepatic porta at Hour 2, small branches of portal vein, sinus hepaticus and around central veins of hepatic lobules at Day 3 and liver parenchyma (esp. in area of lesion) at Day 7 and Week 2. Some of transplanted BMSCs were tightly connected with liver cell to form liver cell cord. The signal intensity changes of MRI corresponded to histological findings at different timepoints.
Conclusion: The transplanted BMSCs are gradually scattered in whole liver (esp. in lesion area) so that it may help to repair hepatic lesions. And the recurring patterns of MR signal intensity changes reflected the condition of distribution, immigration and differentiation of transplanted cells.