Analysis of the functional integrity of cryopreserved human liver cells including xenografting in immunodeficient mice to address suitability for clinical applications.

Background: The availability of well-characterized human liver cell populations that can be frozen and thawed will be critical for cell therapy. We addressed whether human hepatocytes can recover after cryopreservation and engraft in immunodeficient mice.

Methods: We isolated cells from discarded human livers and studied the properties of cryopreserved cells.

Reversal of hyperglycemia in mice by using human expandable insulin-producing cells differentiated from fetal liver progenitor cells.

Beta-cell replacement is considered to be the most promising approach for treatment of type 1 diabetes. Its application on a large scale is hindered by a shortage of cells for transplantation. Activation of insulin expression, storage, and regulated secretion in stem/progenitor cells offers novel ways to overcome this shortage.

Telomerase reconstitution immortalizes human fetal hepatocytes without disrupting their differentiation potential.

Background & Aims: The availability of in vitro expandable human hepatocytes would greatly advance liver-directed cell therapies. Therefore, we examined whether human fetal hepatocytes are amenable to telomerase-mediated immortalization without inducing a transformed phenotype and disrupting their differentiation potential. Telomerase is a ribonucleoprotein that plays a pivotal role in maintaining telomere length and chromosome stability.

Gene therapy for inherited hyperbilirubinemias.

Crigler-Najjar syndrome type 1 (CN-1) is a potentially lethal condition, and is the only inherited disorder of bilirubin metabolism that needs treatment beyond the neonatal period. Currently, orthotopic liver transplantation is the only available cure for CN-1. Because the liver architecture is not disturbed in CN-1 and partial correction of bilirubin-UDP-glucuronosyltransferase (UGT1A1) activity is expected to be sufficient for protection against kernicterus, cell and gene therapies are being developed using the Gunn rat as an animal model of the disease.