The novel anti-inflammatory agent lisofylline prevents autoimmune diabetic recurrence after islet transplantation.
BACKGROUND
Pancreatic islet transplantation has become a promising treatment for type 1 diabetes. However, autoimmune reactivity destroys engrafted islets in type 1 diabetic recipients. The authors' previous studies demonstrated that a novel anti-inflammatory agent, lisofylline (LSF), suppressed autoimmune reactivity and protected nonobese diabetic (NOD) mice from diabetes. In this study, the authors investigated the potential of LSF in preventing autoimmune diabetes recurrence after islet transplantation.


METHODS
Spontaneously diabetic NOD mice received NOD severe combined immunodeficiency islet transplants and were treated with daily LSF injections at 50 mg/kg for 3 weeks. Blood glucose levels were monitored. Serum cytokine levels were measured at 1 and 3 weeks after engraftment. Nephrectomy of the islet-implanted kidney was performed in LSF-treated recipients. Histology of islet grafts was assessed at the end of the study. The effect of LSF on beta-cell function was studied in vitro.


RESULTS
Without immunosuppressants and insulin, the LSF-treated recipient mice maintained euglycemia significantly longer than the saline-treated recipients (mean, >65 days in the LSF-treated group vs. 6 days in saline controls; P=0.0004). Serum levels of interferon-gamma were markedly reduced in LSF-treated recipients at 1 and 3 weeks posttransplant. Diabetes recurred in the LSF-treated recipients after removing the islet-implanted kidneys. Immunohistochemistry showed retention of insulin-positive cells in the grafts of the LSF-treated recipients. LSF preserved beta-cell insulin secretory function in the presence of inflammatory cytokines in vitro.


CONCLUSIONS
This study demonstrates that autoimmune diabetes recurrence after islet transplantation could be prevented by treatment with LSF. LSF and its analogues may have the potential to prevent islet autoimmune destruction in clinical transplantation.
Yang
Zandong
Z
Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Virginia, Charlottesville, VA 22908, USA. zy4q@virginia.edu
Chen
Meng
M
Ellett
Justin D
JD
Fialkow
Lawrence B
LB
Carter
Jeffrey D
JD
Nadler
Jerry L
JL
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D016207:Cytokines / Q000037:antagonists & inhibitors / Q000145:classification / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000517:prevention & control* / Q000601:surgery*; D005260:Female; D006085:Graft Survival / Q000187:drug effects; D018836:Inflammation Mediators / Q000037:antagonists & inhibitors / Q000097:blood / Q000378:metabolism; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D016381:Islets of Langerhans Transplantation; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D010431:Pentoxifylline / Q000031:analogs & derivatives* / Q000494:pharmacology*; D055502:Secondary Prevention; D013997:Time Factors; D014184:Transplantation, Homologous
D000894:Anti-Inflammatory Agents, Non-Steroidal; D016207:Cytokines; D018836:Inflammation Mediators; D007328:Insulin; C025189:lisofylline; D010431:Pentoxifylline