Characterization of Long-Term Survival of Syngeneic Hepatocytes in Rat Peritoneum

Abstract

Hepatocyte transplantation is a potential therapy for both acute and chronic hepatic insufficiency and also for treatment of inborn errors of metabolism affecting the liver. The peritoneum is one site for implantation and has several advantages: cells implanted there can be easily identified and observed, and it has a relatively large capacity. Long-term survival using "pure" hepatocytes in the peritoneum have been disappointing. We hypothesized that cotransplantation of hepatocytes with nonparenchymal cells would help maintain differentiated hepatocyte function. Rat liver cells transplanted intraperitoneally into August rats were sacrificed at 7 days, 1, 3, 6, 9, and 12 months and analyzed for presence, basal proliferation, and functionality of hepatocytes. To demonstrate that ectopic hepatocytes remained susceptible to exogenous growth factors affecting cell proliferation, rats 9 and 12 months after transplantation were stimulated with tri-iodothyronine and KGF. Hepatocytes were identified 7 days to >12 months, by H&E and immunohistochemically, as ectopic islands in the omental fat. Functionality was confirmed by glycogen deposition. Basal proliferation in 7-day rats was 28.0 ± 10/1000 hepatocytes in ectopic islands (cf. 5.70 ± 2.7/1000 in recipient liver). Proliferation in ectopic islands was greater than host liver. Growth factor-stimulated proliferation in ectopic islands induced a 70-fold increase in DNA synthesis. In conclusion, hepatocytes transplanted with nonparenchymal cells survive, proliferate, and function in the peritoneum of normal rats, and respond to exogenous growth stimuli. Their survival and proliferation in the presence of a normal functioning liver has implications for the potential use of the peritoneal site clinically for supplementation of liver function in metabolic disorders.

Growth factors improve gene expression after lentiviral transduction in human adult and fetal hepatocytes

“…However, as well as hepatocyte transduction (Figures 2Ai and 2Bi) there was, in addition, transduction of non‐parenchymal cells (Figures 2Aii and 2Bii) morphologically characterised as hepatic stellate cells. Over 7 days, as described by us and others, there is an increasing proportion of non‐parenchymal liver cells (notably hepatic stellate cells) in adult primary hepatocyte cultures, despite the differential centrifugation used to isolate high purity (>97%) hepatocytes 14. This reflects the higher proliferative potential of the stellate cells and fibroblasts in culture, emphasising the importance of morphological characterisation of transduced cells.…”

Liver tissue engineering and cell sources: issues and challenges

“…Even though hepatocytes can be transplanted into liver, spleen and peritoneal cavity, the therapeutic effect has been found to vary according to the site of transplantation. Intra-hepatic and splenic sites are recognized as the best sites for cell infusion (41) and the peritoneal cavity is commonly used for transplanting encapsulated hepatocytes (42)(43)(44)(45)(46)(47). There are a few reports on complications of cell infusion such as transient hemodynamic instability during cell infusion through the splenic artery and portal vein (48).…”

The Liver Vascular Bed for Hepatocytes Cell Therapy and Tissue Engineering

“…1993;Sakai et al 2010). A recent paper described the beneficial effect for cotransplantation in the peritoneum and the importance of spheroids structure is also stressed (Selden et al 2003;Hamazaki et al 2002;Torok et al 2011). Bioartificial liver support systems incorporating nonparenchymal cells obtained better results in terms of both survival and function of hepatocytes.…”

“…The peritoneal cavity offers a large space for hepatocyte engraftment, and contact with portal flow but the peritoneal surface does not support long-term attachment and survival of liver cells. Attachment to collagen-coated beads or microencapsulation allowed for only minimal improvement (Selden et al 2003;Baldini et al 2008). Co transplantation with non parenchymal cells showed some promise yet, hepatocytes transplanted to the peritoneum or dorsal fat pad do not express genes as those transplanted in the liver (Gupta et al 1994;Selden et al 1995).…”