Control of Liver Tissue Reconstitution in Mesenteric Leaves: The Effect of Preculture on Mouse Hepatic Progenitor Cells Prior to Transplantation

Abstract

Our objective is to control the reconstitution of liverlike tissues at extrahepatic sites using hepatic progenitor cells (HPCs) andin vitropreculture prior to transplantation. We prepared cell-based hybrid grafts by culturing HPCs isolated from fetal E14.5 mouse livers on biodegradable, highly porous 3-dimensional poly-L-lactic acid (PLLA) scaffolds for 1 week in basal medium (the basal condition) or 10 mM nicotinamide (NA) and 1% dimethyl sulfoxide (DMSO) supplemented conditions (the ND-positive condition) prior to implantation. Sections of hybrid grafts cultured for 1 week showed that HPCs grew and spread on the surface of scaffolds under both basal and ND (+) conditions. Most of these cells were albumin (+) and CK18 (+). CK19 (+) cells were also present under the basal condition but not the ND (+) condition. Cultured hybrid grafts were implanted into the mesenteric leaves of mice and removed after 1 month. Transplanted tissues cultured under the basal condition consisted of albumin (+) hepatocyte-like and CK19 (+) biliary epithelial cell (BEC)-like cells organized in duct-like structures. In contrast, integrated tissues cultured under the ND (+) condition alone had differentiated albumin (+) hepatocyte-like cells and were relatively larger than those under the basal condition. Hepatocyte-like cells of transplanted hybrid grafts cultured under both conditions were periodic acid-Schiff (PAS) staining-positive and expressed transcription factors, hepatocyte nuclear factor (HNF) 4 and CCAAT/enhancer-binding protein (C/EBP) α. These findings suggest that combining progenitor cells andin vitropreculture may potentially regulate liverlike tissues at extrahepatic sites.