Mitomycin-C treatment followed by culture produces long-term survival of islet xenografts in a rat-to mouse model.
One of the goals of islet transplantation is to transplant viable islets without host immunosuppression. The present study was designed to determine whether pretreatment of islets with mitomycin-C (MMC) followed by culture enhances islet survival in a rat-to-mouse xenogeneic combination. WS(RT1k) rat islets pretreated with various concentrations of MMC (0, 3.2, 10, 32, 100, 320, and 1000 microg/ml) were tested for viability by in vitro insulin secretory capacity and vital staining of islets. The MMC-treated islets (10 microg/ml) cultured for various periods (4, 20, or 40 h, 3 or 7 days) were transplanted into the renal subcapsular space of STZ-induced diabetic C57BL/6 (B6: H-2b) mice. MMC-treated or nontreated islets were subjected to microarray gene analysis and immunohistological study. Evaluation of in vitro insulin secretory capacity and vital staining of islets indicated that MMC at a dose < or =32 microg/ml is nontoxic and preserves islet function. Marked prolongation of graft survival was noted with half of islet grafts surviving indefinitely (>100 days) when 10 microg/ml of MMC-treated islets was transplanted after 40 h or 3 days in culture, but not when they were transplanted within 4 h following treatment or at 7 days following treatment, indicating that there is a critical culture period necessary for successful islet graft survival. Microarray analysis suggested possible genes for this prolongation with TGF-beta highly expressed in MMC-treated islets subjected to culture for 3 days. Our results indicate that MMC treatment followed by a critical culture period induces marked prolongation of rat islet xenograft survival in nonimmunosuppressed recipient mice, offering a strategy for islet transplantation without immunosuppression.
Gunji
Takashi
T
Department of Surgery I, Fukushima Medical University, Fukushima, 960-1295, Japan.
Saito
Takuro
T
Sato
Yoshihiro
Y
Matsuyama
Shinichi
S
Ise
Kazuya
K
Kimura
Takashi
T
Anazawa
Takayuki
T
Gotoh
Mitsukazu
M
D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D020869:Gene Expression Profiling; D006082:Graft Enhancement, Immunologic; D006085:Graft Survival / Q000187:drug effects*; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007515:Islets of Langerhans / Q000166:cytology / Q000187:drug effects* / Q000276:immunology* / Q000502:physiology; D016381:Islets of Langerhans Transplantation / Q000276:immunology*; D008297:Male; D051379:Mice; D046228:Microarray Analysis; D016685:Mitomycin / Q000494:pharmacology*; D008969:Molecular Sequence Data; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D051381:Rats; D014183:Transplantation, Heterologous / Q000276:immunology*
D007328:Insulin; D019384:Nucleic Acid Synthesis Inhibitors; D016685:Mitomycin