Hepatic reconstruction from fetal porcine liver cells using a radial flow bioreactor.
OBJECTIVE
To examine the efficacy of the radial flow bioreactor (RFB) as an extracorporeal bioartificial liver (BAL) and the reconstruction of liver organoids using embryonic pig liver cells.


METHODS
We reconstructed the liver organoids using embryonic porcine liver cells in the RFB. We also determined the gestational time window for the optimum growth of embryonic porcine liver cells. Five weeks of gestation was designated as embryonic day (E) 35 and 8 wk of gestation was designated as E56. These cells were cultured for one week before morphological and functional examinations. Moreover, the efficacy of pulsed administration of a high concentration hepatocyte growth factor (HGF) was examined.


RESULTS
Both cell growth and function were excellent after harvesting on E35. The pulsed administration of a high concentration of HGF promoted the differentiation and maturation of these fetal hepatic cells. Microscopic examination of organoids in the RFB revealed palisading and showed that bile duct-like structures were well developed, indicating that the organoids were mini livers. Transmission electron microscopy revealed microvilli on the luminal surfaces of bile duct-like structures and junctional complexes, which form the basis of the cytoskeleton of epithelial tissues. Furthermore, strong expression of connexin (Cx) 32, which is the main protein of hepatocyte gap junctions, was observed. With respect to liver function, ammonia detoxification and urea synthesis were shown to be performed effectively.


CONCLUSIONS
Our system can potentially be applied in the fields of BAL and transplantation medicine.
Ishii
Yuji
Y
Department of Surgery, the Jikei University School of Medicine, Tokyo, Japan. yujiyunayuta@jikei.ac.jp
Saito
Ryota
R
Marushima
Hideki
H
Ito
Ryusuke
R
Sakamoto
Taro
T
Yanaga
Katsuhiko
K
D000641:Ammonia / Q000378:metabolism; D000818:Animals; D001652:Bile Ducts / Q000196:embryology* / Q000378:metabolism / Q000648:ultrastructure; D019149:Bioreactors; D018929:Cell Culture Techniques; D002454:Cell Differentiation; D049109:Cell Proliferation; D048430:Cell Shape; D017630:Connexins / Q000378:metabolism; D005865:Gestational Age; D017228:Hepatocyte Growth Factor / Q000378:metabolism; D022781:Hepatocytes / Q000378:metabolism / Q000648:ultrastructure*; D008099:Liver / Q000196:embryology* / Q000378:metabolism / Q000648:ultrastructure; D019164:Liver, Artificial; D046529:Microscopy, Electron, Transmission; D009940:Organoids; D010101:Oxygen Consumption; D012212:Rheology; D013552:Swine; D013556:Swine, Miniature; D019108:Tight Junctions / Q000648:ultrastructure; D013997:Time Factors; D014508:Urea / Q000378:metabolism; D000097002:Gap Junction beta-1 Protein
D000641:Ammonia; D017630:Connexins; D017228:Hepatocyte Growth Factor; D014508:Urea; D000097002:Gap Junction beta-1 Protein