Adipose derived adult stem cells in hepatic regeneration

Abstract

The present invention provides a method to derive hepatic stem cells from stem cells derived from non-liver tissue. In one embodiment of the invention, hepatic stem cells are derived from adipose stem cells. The invention also provides a method of enhancing hepatic cytokine production (e.g., HGF) from ASCs, which may be useful in the regeneration of liver tissue when transplanted in vivo. Tissue culture conditions, including media conditions, are provided.

What is claimed is: 
     
         1 . A method of deriving hepatic stem cells from non-liver stem cells comprising:
 (a) providing stem cells derived from non-liver tissue; and   (b) culturing the stem cells on an extracellular matrix comprising at least one fibrilar matrix protein and in serum-free culture medium comprising hepatic growth factor (HGF),   in which the stem cells derived from non-liver tissue differentiate into hepatic stem cells.   
     
     
         2 . The method according to  claim 1  in which the non-liver tissue is adipose tissue. 
     
     
         3 . The method according to  claim 1  in which the non-liver tissue is tissue from an adult mammal. 
     
     
         4 . The method according to  claim 1  in which the at least one fibrilar matrix protein is selected from the group consisting of collagen I and collagen III. 
     
     
         5 . The method according to  claim 4  in which the at least one fibrilar matrix protein is collagen I. 
     
     
         6 . The method according to  claim 1  in which the culture medium further comprises Oncostatin M, DMSO or both. 
     
     
         7 . The method according to  claim 1  in which the extracellular matrix further comprises fibronectin, matrigel, vitrogen or combinations thereof. 
     
     
         8 . The method according to  claim 1  in which greater than about 70% of the stem cells derived from non-liver tissue differentiate into hepatic stem cells. 
     
     
         9 . The method of  claim 1  in which the stem cells derived from non-liver tissue were further derived from passage in culture. 
     
     
         10 . A method of inducing HGF expression from non-liver stem cells comprising:
 (a) providing stem cells derived from non-liver tissue; and   (b) culturing the stem cells on an extracellular matrix comprising at least one fibrilar matrix protein and in serum-free culture medium comprising EGF, bFGF, or both,   in which the stem cells derived from non-liver tissue produce HGF.   
     
     
         11 . The method of  claim 10  in which the culture medium comprises EGF and bFGF. 
     
     
         12 . The method of  claim 10  in which the culture medium further comprises sodium ascorbic diphosphate. 
     
     
         13 . The method of  claim 11  in which the culture medium further comprises sodium ascorbic diphosphate.