Efficient generation of human hepatocytes by the intrahepatic delivery of clonal human mesenchymal stem cells in fetal sheep

Abstract

Alternative methods to whole liver transplantation require a suitable cell that can be expanded to obtain sufficient numbers required for successful transplantation while maintaining the ability to differentiate into hepatocytes. Mesenchymal stem cells (MSCs) possess several advantageous characteristics for cell-based therapy and have been shown to be able to differentiate into hepatocytes. Thus, we investigated whether the intrahepatic delivery of human MSCs is a safe and effective method for generating human hepatocytes and whether the route of administration influences the levels of donorderived hepatocytes and their pattern of distribution throughout the parenchyma of the recipient's liver. Human clonally derived MSCs were transplanted by an intraperitoneal (n ‫؍‬ 6) or intrahepatic (n ‫؍‬ 6) route into preimmune fetal sheep. The animals were analyzed 56-70 days after transplantation by immunohistochemistry, enzyme-linked immunosorbent assay, and flow cytometry. The intrahepatic injection of human MSCs was safe and resulted in more efficient generation of hepatocytes (12.5% ؎ 3.5% versus 2.6% ؎ 0.4%). The animals that received an intrahepatic injection exhibited a widespread distribution of hepatocytes throughout the liver parenchyma, whereas an intraperitoneal injection resulted in a preferential periportal distribution of human hepatocytes that produced higher amounts of albumin. Furthermore, hepatocytes were generated from MSCs without the need to first migrate/lodge to the bone marrow and give rise to hematopoietic cells. Conclusion: Our studies provide evidence that MSCs are a valuable source of cells for liver repair and regeneration and that, by the alteration of the site of injection, the generation of hepatocytes occurs in different hepatic zones, suggesting that a combined transplantation approach may be necessary to successfully repopulate the liver with these cells. (HEPATOLOGY 2007;46:1935-1945 T he maintenance of cellular homeostasis within the normal liver and during liver regeneration is provided by mature hepatocytes and cholangiocytes and by the intrahepatic (IH) stem cell compartment located in the canals of Hering and the intralobular bile ducts. 1 Recently, another potential source of cells able to provide liver cell replacement has been identified. These stem/progenitor cells consist of hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs) that reside within the bone marrow (BM) but can reach the liver through the circulatory system. [2][3][4][5][6][7][8][9][10][11][12] Because it is clearly evident that the shortage of available human donor organs cannot meet the needs of all the patients awaiting liver transplantation, alternatives to whole-organ replacement are urgently needed. Cell-based treatments, with cells of either hepatic or extrahepatic origin that would be able to repopulate and re-establish a functional liver after administration, could serve as a possible alternative to wholeorgan transplantation.In order to attain this goal, several questions, such as the sour...

Coculture with Mesenchymal Stem Cells Results in Improved Viability and Function of Human Hepatocytes

“…MSCs have been shown to differentiate into hepatocytes in appropriate conditions in vitro and in vivo (1,5). In addition, they can modulate liver injury and promote native liver regeneration (3,23) with improved survival in animal models of liver disease and in pilot clinical studies of liver failure (13,16,17,27).…”

Mesenchymal Stem Cells: Possibilities of New Treatment Options

“…In addition, they represent the origin of stromal cells which are the supportive cells in all tissues (Chamberlain et al 2007 ;Ohishi and Schipani 2009 ) . These cells were fi rst identifi ed by Friedenstein in 1976(Friedenstein et al 1976 ) .…”

“…Bone marrow is also considered as the main source of MSCs. An average of 2-100 MSCs were shown to be present in bone marrow aspirations for 1 × 10 6 mononuclear cells (Dazzi and Horwood 2007 ;Deans and Moseley 2000 ;Abdallah and Kassem 2008 ;Caplan 1991 ;Chamberlain et al 2007 ;Ohishi and Schipani 2009 ;Pittenger 2008 ) .…”

“…There is growing enthusiasm for using these cells in clinical settings due to their easy proliferation and high differentiation capabilities and immunosuppressive properties (Le Blanc et al 2003a ;Le Blanc and Ringden 2005 ;Chamberlain et al 2007 ;Ohishi and Schipani 2009 ;Le Blanc et al 2003b ;Le Blanc and Ringden 2007 ) .…”

Liver Parenchyma Regeneration in Connection with Extended Surgical Procedure - Experiment on Large Animal

“…Overall, whether MSC can significantly contribute to liver regeneration in vivo remains controversial (Dahlke, 2004, Lysy, 2008, Popp, 2006, although MSC can show some features of hepatic differentiation in culture or under immunoprivileged conditions (Najimi, 2007, Ong, 2006. Chamberlain observed differentiation of human MSC into hepatocytes after infusion of MSC into foetal sheep (Chamberlain, 2007) and transplantable hepatocytes were also obtained from heavily growth factor-treated MSC (Banas, 2007, Yamamoto, 2008. Despite the fact that it was not possible to identify transplanted MSC within recipient livers in this model after 14 days, liver hypertrophy was augmented.…”