A human beta-cell line for transplantation therapy to control type 1 diabetes.

A human pancreatic beta-cell line that is functionally equivalent to primary beta-cells has not been available. We established a reversibly immortalized human beta-cell clone (NAKT-15) by transfection of primary human beta-cells with a retroviral vector containing simian virus 40 large T-antigen (SV40T) and human telomerase reverse transcriptase (hTERT) cDNAs flanked by paired loxP recombination targets, which allow deletion of SV40T and TERT by Cre recombinase. Reverted NAKT-15 cells expressed beta-cell transcription factors (Isl-1, Pax 6, Nkx 6.1, Pdx-1), prohormone convertases 1/3 and 2, and secretory granule proteins, and secreted insulin in response to glucose, similar to normal human islets. Transplantation of NAKT-15 cells into streptozotocin-induced diabetic severe combined immunodeficiency mice resulted in perfect control of blood glucose within 2 weeks; mice remained normoglycemic for longer than 30 weeks. The establishment of this cell line is one step toward a potential cure of diabetes by transplantation.

Prolonged survival of mice with acute liver failure with transplantation of monkey hepatocytes cultured with an antiapoptotic pentapeptide V5.

BACKGROUND: Because hepatocyte transplantation has been considered to be an attractive method to treat acute liver failure (ALF), efficient recovery of hepatocytes and maintenance of differentiated hepatocyte functions is of extreme importance. We here report the usefulness of an antiapoptotic pentapeptide V5, composed of Val-Pro-Met-Leu-Lys, in the monkey hepatocyte cultures. METHODS: We evaluated albumin production, metabolizing abilities of ammonia, lidocaine, and diazepam of monkey hepatocytes cultured with V5. The protein expression of apoptosis-associated molecules was analyzed using power blot analysis. An unwoven cloth inoculated with V5-treated monkey hepatocytes was transplanted on the surface of the spleen of both SCID mice and Balb/c mice suffering from ALF induced by 90% hepatectomy. RESULTS: When 100 microM V5 was utilized, ammonia-, lidocaine- and diazepam- metabolizing capacities and albumin production ability were significantly increased in V5-treated monkey hepatocytes. Such hepatocytes showed decreased Annexin V binding and increased the expression of anti-apoptotic and/or cytoprotective molecules, including Ku70, NF-kappaB, IKAP, hILP/XIAP, IkappaB, and CAS. Transplantation of the cloth containing the monkey hepatocytes significantly improved blood levels of glucose and ammonia and encephalopathy score and prolonged the survival of the mice with ALF. CONCLUSIONS: The present work clearly demonstrates the usefulness of V5 for maintaining the functions of monkey hepatocytes in tissue culture.