Transfection of human pancreatic islets with an anti-apoptotic gene (bcl-2) protects beta-cells from cytokine-induced destruction.
Apoptosis has been identified as a mechanism of pancreatic islet beta-cell death in autoimmune diabetes. Proinflammatory cytokines are candidate mediators of beta-cell death in autoimmune diabetes, and these cytokines can induce beta-cell death by apoptosis. In the present study, we examined whether transfection of human islet beta-cells with an anti-apoptotic gene, bcl-2, can prevent cytokine-induced beta-cell destruction. Human islet beta-cells were transfected by a replication-defective herpes simplex virus (HSV) amplicon vector that expressed the bcl-2 gene (HSVbcl-2) and, as a control, the same HSV vector that expressed a beta-galactosidase reporter gene (HSVlac). Two-color immunohistochemical staining revealed that 95+/-3% of beta-cells transfected with HSVbcl-2 expressed Bcl-2 protein compared with 14+/-3% of beta-cells transfected with HSVlac and 19+/-4% of nontransfected beta-cells. The bcl-2-transfected beta-cells were fully protected from impaired insulin secretion and destruction resulting from incubation for 5 days with the cytokine combination of interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha, and interferon (IFN)-gamma. In addition, the bcl-2-transfected islet cells were significantly protected from cytokine-induced lipid peroxidation and DNA fragmentation. These results demonstrate that cytokine-induced beta-cell dysfunction and death involve mechanisms subject to regulation by an anti-apoptotic protein, Bcl-2. Therefore, bcl-2 gene therapy has the potential to protect human beta-cells in pancreatic islets, or islet grafts, from immune-mediated damage in type 1 diabetes.
Rabinovitch
A
A
Department of Medicine, University of Alberta, Edmonton, Canada.
Suarez-Pinzon
W
W
Strynadka
K
K
Ju
Q
Q
Edelstein
D
D
Brownlee
M
M
Korbutt
G S
GS
Rajotte
R V
RV
D017209:Apoptosis / Q000235:genetics*; D002478:Cells, Cultured; D016207:Cytokines / Q000494:pharmacology / Q000502:physiology*; D053938:DNA Fragmentation / Q000187:drug effects; D005822:Genetic Vectors; D006801:Humans; D007150:Immunohistochemistry; D007371:Interferon-gamma / Q000494:pharmacology / Q000502:physiology; D007375:Interleukin-1 / Q000494:pharmacology / Q000502:physiology; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism*; D015227:Lipid Peroxidation / Q000187:drug effects; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology*; D011994:Recombinant Proteins / Q000494:pharmacology; D018139:Simplexvirus; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology / Q000502:physiology
D016207:Cytokines; D007375:Interleukin-1; D019253:Proto-Oncogene Proteins c-bcl-2; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma